If you are using binary only graphics card drivers does the problem also
happen without them never loaded at all?
I had a machine that would not suspend properly until some time part way
through the 2.6.25 kernel. It might be worth reporting whether you have
the same problem (perhaps by using a live cd) when you use a 2.6.26 or
I do know that it *does* suspend fine *with* the binary driver, provided the SATA drive isn't in the docking station, and that the laptop has been suspending fine like this for several months / kernel revisions.
That's definitely not the case here.
I have just replicated the problem exactly without the fglrx module (ever) loaded at all, and using the very latest radeonhd DDX driver instead. So this really IS *just* to do with the SATA drive in the docking station.