Strange delay related to mouse?

[jw]

I recently upgraded xfce from 4.4 to 4.6 (this is FreeBSD 7.1-RELEASE)

It is mostly working, but I notice that certain actions are delayed
when I don't move my mouse enough.

For instance, I will
1) click on a terminal window
2) type on the keyboard
3) nothing will change on screen
4) I move my mouse a bit, and suddenly the text I typed shows up!

But this doesn't seem like merely a repaint issue.
The same thing happened when I shut down from the panel.
I clicked "shutdown", then let it sit. It did not shut down.
The screen looked partially-cleared of windows, but it had stopped
doing anything (I waited several minutes).
Then I moved my mouse and it proceeded to shut down normally!

I don't know if this is some delay or setting that can be configured,
an xorg issue, or an xfce issue (or something completely separate).
It just won't proceed in certain cases without getting mouse input...

Anyone know anything about this?
I haven't found anything relevant from searching around for a bit...

Thanks for any help
-John