As I said in the PM, you're not limited to what it detects as optimal frequencies. When I clicked "detect optimal frequencies," it said 382 I believe. Just drag the slider over to higher settings and test them. If they're stable, you can try to go higher if you want. If you see artifacting or other video oddities, tone it down and try again. All cards and setups are different, so even if we had the exact same hardware, we likely wouldn't have the same results.
By the way, I scored nearly 21,000 in 3DMark03 and over 9500 in 3DMark05 at 400/1.1 and the temperatures didn't seem to be affected at all! Now, if only I could solve the CPU temperature mystery.