Well as long as u are happy
But it should be able to be blank...
i never touched that.. and i remember on tests that it worked...
There could be another problem.. in your category configuration..
I just tested it without Limit Categories and it works also..
I have no member categories
Create another normal user.
Make sure that other user can see images when browsing gallery.. not only the thumbnails but also the big images.
Then check if he can see forum home block.
PS: But if it works... ntrs (Never touch a running System)