>I'm running the code in a VFP com server which doesn't accept what you said.

Oh, that makes sense then.

>This only happens if i'm acessing the com server in the same machine where the IIS is installed. If acess that same machine from another one the error doesn't occur.

Yep, thats odd. Just a guess at a workaround: what would happen if instead of setting the expiration date in the VFP COM, you simply returned a string to the ASP Page and let the page set it itself?