I have a box running XP Home (SP2) connecting to a Windows 2003 server in a domained environment. (This is one of several XP Home machines in the office and this problem is unique to this specific machine.) The folder on the drive is mapped as x: so when a specific file is to be found the normal process would be to right click the drive icon and select 'search' from the context menu.
The problem is that the search runs as an infinite loop. As soon as all of the directories are searched for the file (with the results displayed) the search will automatically rerun itself starting with the root directory and proceeding through all of the subfolders. As a test I turned off the 'search subfolder option' and after searching the one folder it would pause for a couple of seconds then restart the search - as evidenced by the [search now] button greying out and the [stop search] button becoming active momentarily. (When the search subfolder option is checked the same behavior exhibits - I will stop the search with the [stop search] button but after a second or three the search will restart itself.
The system is believed to be malware free - Norton Antivirus and Microsoft AntiSpyware.