Might be a bug, but not sure. Which document repository type are you using for those documents? Database, FTP, or Shared?

Also, there is a setting that controls where we will check the file size before we allow approving a document - if you don't need it you can turn it off.

This is the setting I mentioned above:

I use Shared type. 

Does edit and check in work without any problems? Also, do you need that setting turned on? I don't think many customers actually need it.