Here's a good one for you.... I found some History weirdness. I'm not sure how to word this, so I'll describe how to reproduce it...
In Develop module, pull up a photo to work on. Make a couple of changes so you have some history - for instance, adjust the Exposure and Clarity. Now, pick an adjustment that's been changed - say, Clarity. Click on the number on the right side of the adjustment, as if you were going to change the number by hand. It should change to an editable field with the existing setting highlighted. Now, while that number is highlighted, change something else in a way that won't un-highlight the setting you selected above - for instance, double-click the word Exposure to set Exposure back to its default. The highlighted setting should still be highlighted. Now hit Enter to accept that setting and save it.
Ok - what you've just done, in my example, is adjust Clarity and Exposure. Both settings should have been made and you should see their effects on the picture. BUT - you'll only have a history change for the Clarity adjustment!
There's also the weird alt-click on adjustments behavior I noted in another thread. I've seen more weirdness with other files on this. The short form is that, when adjusting sharpness settings at 1:1 magnification, if I alt-click any of the four sliders, I sometimes don't see the display at all - the normal image remains, or sometimes see an all white screen. In all cases, the adjustments still work - just that the alt-click display doesn't. I haven't gotten enough of a handle on this to file a well described bug, at this point....
Edit to add - 1.1 seems to be less stable for me, and is definitely slower than 1.0 on my system (Athlon64 3200+ w/ 2GB RAM, running XP). However, I can't say this is an apples to apples comparison - I didn't have anywhere near the number of photos in the library as I have after doing the upgrade.