My mpegs have turned into zip files????

[stehardy]

have never had any problems with limewire, however the past week or so every time i download an mpeg it seems fine, plays ok, then 24/48 hours later when i switch my pc on, it has changed from an mpeg into a zip file.

when i click on it it asks me if i want to extract the file, i click yes and it turns it back into an mpeg icon, but says "file corrupt on transfer" and wont let me play it.

Any ideas as this is driving me mad, its happening with every single download i do. Is there a virus? have removed limewire completely and reinstalled it but its doing the same.

Have emailed tech support but had no reply.