Automatically unzipping files

[Rhodan]

When downloading multi-part zipped archives, Mac OS has the annoying habit of automatically unzipping each file as it downloads. This results in loads of errors for each file unzipped until all the files have downloaded.

Is there a way I can turn this default behaviour off?

 

[Rhodan]

I'm using Firefox.

I thought it was normal behaviour for Mac OS to automatically unzip files for you as they are downloaded?

 

[Rhodan]

I had that rubbish, Stuffit Expander installed, I think that might have goosed something up then.

This is extremely frustating that I cannot simply turn it off, or that an application that was previously installed is still causing this behaviour?