i tried to reproduce your problem, but with no luck.
Tried with FF 15.0.1 and 17.0.1, with HFS 2.3 (build 282) and default template.
I set up an account, and put a redirection to a folder, then restricted that folder to that account.
When i log in in FF i get redirected in no time.
My suggestion is
1. try setting up a blank hfs for testing purposes and see if you get the problem
2. if you don't get the problem, try to copy all sensible settings that may be involved in the problem from the real platform to the test platform, until you get the problem. You'll know what's causing it.