To reproduce problem:
1: http://www.demozzz.com/dolphin720rc/forum/groups/forum/HL-Test-Group-0.htm
2: Click on 'Test Post' topic.... observe the url that is displayed by browser when you hover on link
3.Proper link is: http://www.demozzz.com/dolphin720rc/forum/groups/topic/Test-post.htm
4: Link you are forwarded to is: http://www.demozzz.com/dolphin720rc/forum/topic/Test-post.htm
Refreshing the page at this point will display a permission error. The topic title links to the correct url.