WinXP shared drives issue

I have an a开发者_开发知识库pp in .NET that writes some really small files (2k-40k) on some network shared drives. These network shared drives are on another WinXP machine. The issue I'm having is that the app is able to write to the shared drive, but unable to open the same file using:

Process.Start(fullPathFileName);

The error I'm getting is "The system cannot find the file specified". By browsing the shared drive I can see the file being created and I can open it from WinExplorer without any issues. Any ideas ?

It looks like a security issue to me. I am sure that you have tried looking at the files permissions, but in case you have not... :)