Opening FLA saved from Windows 7 into OSX causes objects to shift

Hi,

I've been working on a project on a Windows 7 machine using Flash CS6, saved the file as FLA and then sent it to my work to continue working on their Mac OSX computers. The problem is, when I opened the file, a lot of the vectors were misplaced and had resized slightly which caused problems with my masks.

Is this a known bug, or to do with the way it's saved?

Thanks.