Unable to Open File

Can't open some GIF files.

[BeeDeeDubbleU]

I have a problem when someone sends me files attached to email. Outlook reports that it is "Unable to open the file" on some gif images but not others. When I save the image first I can then open it normally. What is annoying me is that I had this self same problem on another PC four or five years ago and I fixed it but I cannot remember how :(

Any ideas?

[mack]

Is it maybee related to some security took that you have installed?

Mack.

[BeeDeeDubbleU]

It could be but then why would it allow some gif's to be opened and not others? And why would it allow them to be opened after saving?