Comment 4 for bug 884387

To be clear, I can reproduce this with any progress bar. The easiest is a file copy:

1) Start file copy of a reasonable (10's to 100's) of files which will last a few minutes
2) Peek at `top`, notice compiz is using 15%+ CPU and system has become extremely laggy
3) Minimize progress bar, notice compiz has dropped to 4% CPU and system is responsive

This is the first performance issue I've yet encountered with my setup. The progress bars really aren't that dazzling to warrant the performance hit I'm seeing.