Really? Actually, QA is my prophecy . And as QA I have to admit that firmware 4.2007 (this one with skype) has slightly worse quality than "default" firmware (version 3.200 IIRC). Sorry but that's true, at least it's my experience. I also do not know if Nokia extensively tested SDHC support but if QA processes adjusted properly, this bug not seems to be very hard to catch in test environment. Just buy bunch of cards from different vendors and play with your n800 devices and these cards a bit. Actually I'm surprised such big corporation has failed to perform proper testing.
Talking about QA... one way to improve it is to "outsource" this to "free beta testers". (Some might say that we are all free beta testers... ) Lately more and more IT specific software has been released for testing in beta status (RTComm, Videocenter, etc...) for people to test/try. I wish also the new Firmwares would be made available as beta. I hope this method has proven beneficial tool to Nokia to improve the software quality, and they would continue and expand its usage.