TIH 2010 unbelievably slow UI redraws

The user interface takes 3 seconds or longer to redraw a list of backups. If I scroll through the list, it takes another 3 seconds to update the list. The whole list flickers during this time. This is most pronounced in the "Browse For Location" dialog listing about 30 backups.

The PC in question has an Intel Core 2 Quad CPU, 8GB of RAM and ATI Radeon HD5770 card, so the PC specs are certainly not to blame. I'm running Win7 x64.

Any ideas on how to fix this?