Try installing the RC (release candidate) version of the service pack 1:
Windows Vista Service Pack Download - Softpedia
MS will be releasing the final version any day now and you can find it already if you look hard enough, I've just gave this link for ease. You can always uninstall this one and install the later version.
The service pack does deal with problems associated with using Hibernate, good luck.

update: I've just read that the service pack will be released on Tuesday so it may be worth waiting till then.

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