Google quietly updated their Google Play Store, formerly known as the Android Market to Version 3.5.16. It should find its way to you in the coming days and reportedly fixes a few issues some users were having with 3.5.15 like force closes and/or disappearing purchased apps. I checked my Galaxy Nexus and Galaxy Note and one had updated where the other one had not. So I have provided a download link below should you want to manually install the latest update.
Download Google Play Store 3.5.16
Thanks to AndroidPolice and PhanDroid for being on the ball with this one ^_~.