Ah, I think I was wrong, is not the Windows version, I think the problem is that the windows 7 computers have SP 1 installed! Jeez, how could this happen? :)
[Update]
Yeah, SP 2 solve the issue, need to talk now with network guys so they check that all computers have SP 2 installed and if it not then update it
[/Update]
"The five senses obstruct or deform the apprehension of reality."
Jorge L. Borges?
"Premature optimization is the root of all evil in programming."
Donald Knuth, repeating C. A. R. Hoare
"To die for a religion is easier than to live it absolutely"
Jorge L. Borges