Excel being "poopy" and not opening files since update.

Hello everyone!

So i was using excel 2008 for mac fine the other day, downloading and opening excel files fine.

Then after the update my excel decided its had enought and it packed it in.

I can start a new excel file, but when i go to open those files i have downloaded this message is displayed.

"The document '4 pm survey data-3.xls.xla' could not be opened. The file is not in the right format.

The file might be corrupted, truncated, or in a different format than you expect."

Please help!!!

SAm