Yes, the time shown in the administrative console (in IE/Windows/Parallels/OSX) falls behind actual time as I leave the window open.
The time in OSX and Windows seem to be synchronized - they don't seem to differ - I have not seen OSX and Windows/Parallels have any time difference. But I will admit I haven't kept close watch on it.
At this very moment, OSX and Windows say the time is 6:43 and the administrative console is showing 6:41. The difference grows larger the longer the administrative console is left open.
As I have said before, if I logout of the administrative console and log right back in, the time is correct.
I have cleared the Java Cache in Windows(numerous times).