Google are releasing yet another update to the Google Play Store (formerly Android Market), in yet another attempt to iron out the many bugs that came with the new re-vamped store.
Version 3.5.16 promises to fix a lot of bugs, hopefully stopping force closes, and allowing users who were unable to download paid apps, the ability to do so again.
The new update should be rolling out over the next few days, but if the bugs are really affecting you, you can download the APK here.