print spooler blocking

I have a print spooler problem. The servers are Windows 2003 standard edition and the printers are Samsung 2010 (laser) and HP 1010 (laser).
The print Spooler service is blocked sometimes. It is happening apparently without any rule , without any error message for users who are tryng to print documents from the application they are using. There are cases when the application is OK , but there are cases when the system is blocked. If I stop Print Spooler and then I am starting it again , the problem is solved.
Next lines are a few errors in Event viewer.
08-05-07      5:32:45 PM      Microsoft Office 10      Error      None      1000      N/A      Faulting application excel.exe, version 10.0.4302.0, faulting module excel.exe, version 10.0.4302.0, fault address 0x000069aa.      
08-05-07      5:24:30 PM      LPR Print Monitor      Warning      None      2004      N/A      Printer ramona1010 on host 213.164.252.59 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
08-05-07      4:36:35 PM      Application Error      Error      -100      1000      N/A      Faulting application FisaCont.exe, version 1.0.0.187, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x000047cc.      
08-05-07      4:33:05 PM      Application Error      Error      -100      1000      N/A      Faulting application FisaCont.exe, version 1.0.0.187, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x000047cc.      
08-05-07      3:11:08 PM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
08-05-07      2:58:11 PM      Application Hang      Error      -101      1002      N/A      Hanging application cars.exe, version 2.0.2.11, hang module hungapp, version 0.0.0.0, hang address 0x00000000.      
08-05-07      2:52:50 PM      Winlogon      Information      None      1002      N/A      The shell stopped unexpectedly and Explorer.exe was restarted.      
08-05-07      2:41:21 PM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
08-05-07      2:27:23 PM      Application Hang      Error      -101      1002      N/A      Hanging application cars.exe, version 2.0.2.11, hang module hungapp, version 0.0.0.0, hang address 0x00000000.      
08-05-07      1:57:18 PM      Application Hang      Error      -101      1002      N/A      Hanging application FisaCont.exe, version 1.0.0.187, hang module hungapp, version 0.0.0.0, hang address 0x00000000.      
08-05-07      1:56:57 PM      Application Error      Error      -100      1000      N/A      Faulting application FisaCont.exe, version 1.0.0.187, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x00004850.      
08-05-07      1:40:55 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application FisaCont.exe, version 1.0.0.187, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x0000c478.      
08-05-07      1:40:44 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application raptest.exe, version 1.0.0.32, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x000047cc.      
08-05-07      12:59:32 PM      Application Error      Error      -100      1000      N/A      Faulting application FisaCont.exe, version 1.0.0.187, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x0000c478.      
08-05-07      11:13:27 AM      Application Error      Error      -100      1000      N/A      Faulting application raptest.exe, version 1.0.0.32, faulting module oleaut32.dll, version 5.2.3790.1830, fault address 0x000047cc.      
08-05-07      10:52:13 AM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
08-05-07      9:53:52 AM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
08-05-07      1:20:31 AM      SceCli      Information      None      1704      N/A      Security policy in the Group policy objects has been applied successfully.      
07-05-07      6:56:47 PM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
07-05-07      4:56:45 PM      LPR Print Monitor      Warning      None      2004      N/A      Printer aprovizionare_d2 on host 213.164.252.56 is rejecting our request.  Will retry until it accepts the request or the job is cancelled by the user.      
07-05-07      4:39:51 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application spoolsv.exe, version 5.2.3790.1830, faulting module ntdll.dll, version 5.2.3790.1830, fault address 0x00032335.      
07-05-07      4:39:49 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application spoolsv.exe, version 5.2.3790.1830, faulting module ntdll.dll, version 5.2.3790.1830, fault address 0x0001c950.      
07-05-07      4:39:46 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application spoolsv.exe, version 5.2.3790.1830, faulting module ntdll.dll, version 5.2.3790.1830, fault address 0x000327f9.      
07-05-07      4:39:42 PM      Application Error      Information      -100      1004      N/A      Reporting queued error: faulting application spoolsv.exe, version 5.2.3790.1830, faulting module ntdll.dll, version 5.2.3790.1830, fault address 0x0002fd3a.