Single Excel file can not be opened

I have a single excel file titled test1.xls that I can not open from one workstation.  If I change the name, I can open it.  I have the file local, on the network, as an email attachment,  it doesn't matter.  As long as it has that name it will not open.  Everyone else that tries can open it without a problem.  They all have same version, Excel 2003 on XP Pro. I have to keep the filename what it is because so many others are linked to the file already.  It was fine up till about a month ago then just suddenly stopped.  I've cleared all temp files, cache. Not sure what else to try.

Message says: Can't create file: test1.xls. Right click the folder you want to create the file in, and then click properties on the shortcut menu to check your permissions for the folder.