Can't change clock speed on one brand 7950 after boot with BAMT?

[suchcoins]

Using BAMT/Ubuntu I have one card that I can freely change the core/mem clocks after boot.

But another 7950, after BAMT boots, nothing can change the clock. Not aticonfig, not atitweak, not cgminer directly.

Note that BAMT does properly initialize the clock during boot as per the settings in cgminer.conf

I am trying to figure out how it does that and with what utility.

Is it maybe an X11 problem where once it is set it is not releasing its lock?

Only thing I can do is change the settings in cgminer.conf and cold boot again.

aticonfig/atitweak can read the clocks but attempting to change them fails

yet the other brand card can change freely

I can change the fan speed without a problem but nothing else.

ideas?