I have 2.6.28 SL kernel running and have run equo deptest and equo libtest , think this also helps to bypass errors as mentioned above as was installed as part of previous equo virtualbox-bin install extra's.
Although 2.6.28 was installed during the entropy update I don't have it running as, presumably, some extra work needs doing - attempting to run it gives me a flashing cursor instead of x. Is it a prerequisite of Virtualbox 2.1.2?
Here is the relevant part of the original update session and there were no errors reported. I did note the instructions at the end to edit /etc/X11/xorg.conf but was a little perplexed by there not being an "InputDevice" section.