Do you have AMD Cool'n'Quiet enabled?

No i dont think so. Anyway now its only doing it to Core 0 so im totaly confused loool

Really sounds like Cool'n'Quiet. It will drop multipliers on cores being used less to reduce heat output. Check your BIOS.

i went into my BIOS and the Cool'n'Quiet option is faded out and i cant select it. It is in the disabled option. So i think it is off.

Maybe the processor is sending the instructions to drop the multiplier by itself?
It's a long shot but it makes sense to me.
AMD's Cool 'n' Quiet has been around for a long time (since Athlon 64 I believe) but now they talk about the Phenom II x6 like it's something new, saying that it has the ability to adjust the multiplier for INDIVIDUAL cores that aren't being used. That leads me to believe that there is something special about the processor itself, rather than the BIOS power saving features.

What I'm getting at is that I don't think it's the motherboard that's doing it. Instead, maybe it's the processor doing its own thing, which is was designed to do.

Turn your power saving mode off, in the bios and OS, or your AI overclocking is going batty in that case switch to manual in bios.

Did a bit of research, and the 1100T has Cool'n'Quiet embedded at the chip level. It is always on, and can't be disabled, which is why it is greyed out in your BIOS page. Changing power saving modes etc. will not change this behavior, and there is no easy way to force it to not downclock. Turns out any chip with Turbo from AMD will have it locked on as the overclocking is based on the EXACT SAME PROCESS as the Cool'n'Quiet underclocking, and turning it off will potentially slow the system down when being heavily used.

Something I've never researched, but it makes sense. Kind of a preview of what we will be seeing in the Bulldozer processing matrix (with so much more)!

Added: Turns out the 990FX boards will have the ability (assuming it is programmed into BIOS) to stop underclocking without locking out Turbo, but no clue if this works with Phenom II chips. It is technically a Bulldozer feature set.

@eire1274
Cool, I was right! :D

Yup, that's it. My Q6600 does the same stuff, saves on power consumption when there's nothing going on. My core goes from 2.4 to 1.5 when I'm not doing anything. Leave it enabled, it's a good thing and doesn't effect your systems performance at all ;)

Caught me off guard. I thought that feature was a Bulldozer exclusive, but AMD can never keep anything cool secret... it always sneaks its way out early! LOL!

Mine Q6600 does the same thing... lol.. I'll try turning power save off. :)

Well you guys turned out to be right. i managed to overclock to 4.5Ghz and i see no cpu multiplier drops when i need it so its fine. Its just i had this cpu in a previous build and i didnt see this before so i was confused.

Thanks soo much again.