Yes, if you import your bookmarks again, they should have the correct date.
We did post on the Yahoo! Group a while ago to let people know about the forums (http://tech.groups.yahoo.com/group/ydn-delicious/message/2109). We haven't abandoned the Group; we still respond to the occasional question posted there. It's a good archive to keep around.
In Delicious, as you can see, it is listed as 31 Dec 2002.
Sorry if I sound frustrated. I was so confident in your advice above that I've been adding bookmarks to Delicious over the last 2 days. Besides the time I wasted importing, I'll now have to re-add all the bookmarks I added to Delicious -- once the bug is fixed, that is, and I spend another hour re-importing all my Netvouz bookmarks.