I get these almost every time I alt-tab, restarting the computer fixes it for a while and then it starts to act up again. I'm running Win7 SP1, AMD FX-6300, a GEForce GTX 750Ti, drivers were all updated last week after I started experiencing this constantly, instead of once every few days.

Problem Event Name: AppHangB1
Application Name: ffxiv_dx11.exe
Application Version: 1.0.0.0
Application Timestamp: 5c76c283
Hang Signature: 9a4e
Hang Type: 1
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 4105
Additional Hang Signature 1: 9a4e69b37cb58fbbca6b132e8e657036
Additional Hang Signature 2: 24b3
Additional Hang Signature 3: 24b322d20887a57626ee3ec8f62be426
Additional Hang Signature 4: 891c
Additional Hang Signature 5: 891cfb0454b4288f7b2b14bfdd4fe3db
Additional Hang Signature 6: d6e5
Additional Hang Signature 7: d6e50473100bdba763206f04c73c1e28