This is probably just me being thick, but…
I log in today, and find the timezone set at GMT-4. I thusly set it to GMT, only to find it’s an hour out. I set it back to GMT-1, which would display the right time, but it doesn’t shift from GMT. I try a different approach, and set it to GMT-2. It works, goes to GMT-1, then promptly on to GMT-2, an hour out the other way.
Argh!
I set it back to GMT-1, and it defaults back to GMT/
What am I doing wrong? 
Same here; try messing with the “detecting Daylights Savings Time” option. I wrestled with it for a good 5 minutes before giving up on it. BUT IT’S NOT FRIGGIN’ 9 PM OR 5 PM, IT’S 6. ARGH.
The time option still isn’t working correctly. I’m going to try troubleshooting it tonight.
Just a little update on this (not a gripe, I know the admins are very busy)… we’ve now switched over to summertime in the UK, and my forum clock finally shows GMT-1… putting it out an hour in t’other direction. :-/
edit: sorted, all I had to do was set DST to “always off”
Merl, it isn’t working because you have the server clock set for DST time.