I have seen increased lockups with 10.9.2. I replied because mine seem also to involve external displays (and/or Thunderbolt accessories). A possibly-related

I have seen increased lockups with 10.9.2. I replied because mine seem also to involve external displays (and/or Thunderbolt accessories). A possibly-related issue causing app lockups (Matlab) was caused by an old Java runtime interacting with multiple displays. Updating JRE fixed that. I have also gotten system-wide lockups on Thunderbolt plug-in (never used to happen with 10.8).