I installed 4.5 the other day, but didn't do my first import until tonight.
Everything seemed to go OK, but the first time I tried to apply any new keywords with the stationary pad, the app crashed immediately. I sent in one crash report and then tried 2 more times with the same result.
So I went back to 4.4.
When I then imported the files into Lightroom, Lightroom reported a few of the files damaged, so I think perhaps the import went badly. I might try again in 4.4 and see if it provides any insight.