in your cpanel, I went to the error logs and saw the following error:
[Thu Aug 05 16:00:28 2010] [error] [client 188.8.131.52] SoftException in Application.cpp:601: Directory "/home/thomasma/public_html/powergallery" is writeable by group, referer: showthread.php?t=15160
I then opened the file manager in the cpanel and selected the powergallery folder. Along the top, I clicked the change permissions link and set the permissions as:
User: Read, Write, Execute
Group: Read, Execute
World: Read, Execute
the gallery seams to be working now.