Hi Alex,
I
tried to generate the problem you describe on a Windows box here
in the lab and it worked fine. So I have two generic pieces of
advice that may solve the problem:
1) Make sure you have the most current driver for your
graphics card installed.
2) If you have multisampling turned on (Favorites->Side
View, Effects tab) try turning it off.
If neither of these help, please use Help->Report a Bug to
submit a bug report. That method will give us a lot more info
about your system hardware and software configuration. Also if
you can please attach a session file to generate the image with
and details about what your settings were in the image-save
dialog. Thanks!
--Eric
Eric Pettersen
UCSF Computer Graphics Lab