A big YES.
I have seen both FireFox and Safari acting differently between Win, Mac and Linux systems. Specially around places with significant JS and advanced CSS implementations.
I personally have not seen differences in IE within different Windows versions.
manpreet Best Answer 2 years ago
I'm about to start some cross browser testing of a design.
In your opinion is it worth testing browsers across a number of operating systems? As the browser is using the same rendering engine will the design likely be the same or are there inconsistencies big enough to warrant testing on different platforms?
For example, is it worth testing IE9 on Windows 7 and Vista?
Is it worth testing Safari on Mac and Windows? If I do this is it worth testing on different versions of Windows?
If I test Firefox in Windows is it worth testing on Linux and Mac?