I have seen this issue come up too many times, and I would like to fix the issue permanently! What happens is when a user opens a TIFF image, it uses their default TIFF viewer software which is either Microsoft Document image writer or Windows picture and fax viewer. In some situations the image will open all blurred or blobbed up which is impossible to read, but if opened in a different TIFF viewer you can see the TIFF just fine. This issue is happening with Windows XP professional PC's with SP3.
I have tested this on other users and it will work fine in both TIFF viewers. I can also reproduce the same issue in some cases with other users/PC's. I have done some research and Microsoft updates have been some of the leading cause to replace their default TIFF viewer to a different TIFF viewer, but I have not seen anything relating to this issue. We are using WSUS to deploy our updates, which should be consistent across the board on any updates that have been deployed.