After downloading some samples and stuff I found the file extension had changed to MGPA which doesn’t seem to load into Acid. can these files be converted to mp3 or wav?

??? That is really strange. Most files here are MP3. Some samples are zipped as wav. I’ve never heard of MGPA. My guess would be iTunes.

Your system is auto-assigning / changing the file extension upon download. You should be able to manually change the extension back to mp3 or wav if cannot figure out how to switch the auto assign off. : )