Microstutters with Hyper Threading on.

I have been having a problem with games having a constant video stutter even with them emulating at 100% or higher. Kirby's Return to Dream Land was one of the most apparent, and after doing a lot of fiddling with all the settings to no avail, I finally decided to try some bios tweaking. Long story short, I decided to try turning off hyper threading, and after continuous testing and turning it back on again it is obviously the culprit.

I searched the forums and could find nothing mentioning HT being an issue but did run across other threads about stuttering. Is this a know issue?