Overclocking HD3650

I have a Diamond HD3650 1gb DDR2 gfx card.

I want to try to overclock it to see if it makes some difference- but overdrive will only let me overclock it from 725 core and 400 mem to 725 core and 400 mem.

This is not a typographical error- overdrive doesn't let me overclock.

ATI Tool 0.26.....

well, i tried it. It didn't recognize my clocks for some reason.

It said I was running a 677 core and 167 mem or something like that.

I didn't bother going any further with that program.

Are there any other things I could try? I am NOT getting a new GPU since I cannot buy online, and best buy is super overpriced compared to newegg. (Well, the HD4870 appears to only have a $50 markup or so, but it is HUGE overkill for my cpu and my psu would die- my E2160@2.02ghz is best suited to an HD4670 or 3870 I think, but those are now not a big enough improvement to justify paying another $120ish for.