I am having this same issue after the patch yesterday. Last night it would let me play for about 15-20 between crashes now i cant even log in. Event Details as follows:

Problem signature:
Problem Event Name: APPCRASH
Application Name: ffxiv.exe
Application Version: 1.0.0.0
Application Timestamp: 54f4ae94
Fault Module Name: ffxiv.exe
Fault Module Version: 1.0.0.0
Fault Module Timestamp: 54f4ae94
Exception Code: c000001d
Exception Offset: 0004fb4d
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

Anyone have any ideas? =(