Foursquare has been updated to v5.5 NO change log appears to be available, and with the small jump in version, it should be safe to assume this version has some minor bug fixes. Your device does require a reboot after install.
About: Foursquare helps you explore the world around you. Meet up with friends. Find places to go. Save money with Specials. Nearby friends view is back! Tap the friends icon to switch between all activity and nearby friends.
While on the go, you can easily tell friends where you are, share pictures, get their comments (“I’m right around the corner, I’ll stop by to say hello”), and get insider tips and reviews (“order the Lobster Ravioli; it’s the best dish by far.”). Tons of places offer discounts and freebies to the foursquare community, and you earn points and badges for doing the things you love. If you want, you can easily post your proudest check-ins to Facebook or Twitter. It’s like the old playground game, four square, but way more fun.