CPU scaling problem with E6540

Hello,

I have a problem with the CPU scaling of my E6540 and the docking station as well as using 90W poower suppy.

When using the 90W power supply, the laptop decides it does not get enough power to charge and scales down to maximal 400MHz. This may be intended, still 90W should be enough to maintain a running laptop. I would really like to use the nice slim 90W power supply when travelling, but this seems not to be possible.

The bigger problem is, that when connecting to the docking station, the laptop sometimes scales down as well. This, unfortunately is randomized and a workaround is to connect and disconnect the laptop several times. Though this is very annoying.

I am mainly using Linux (gentoo), though the scaling is BIOS regulated and thus affects Win7 as well. It is obviously possible to remove the symptoms when turning off the CPU-scaling in the BIOS, but then the consumption and heat of the laptop goes up rapidly, which is not desireable as well.

Is the incompatibility with the 90W supply intended and my docking station faulty, or are these known BIOS issues, which may be removed in the future?