A week or so ago I upgraded to STS 2.92/Grails 2.0.4. Everything was fine for a few days, but then I began to get GrailsContextLoader errors on run-app (localhost debug in STS). I've tried any number of tricks (build path reordering, cleaning, clearing .grails and refreshing dependencies, reviewed config files, etc) to shed light on the problem but nothing seems to have any effect. My classpath clearly references hibernate-core-3.6.10.Final.jar which contains org.hibernate.cfg.Configuration and there are no duplicate hiberate jars that I can see. Any clues?

Code:
| Error 2012-06-11 13:55:32,822 [pool-5-thread-1] ERROR context.GrailsContextLoader  - Error executing bootstraps: org/hibernate/cfg/Configuration
Message: org/hibernate/cfg/Configuration
    Line | Method
->> 2442 | privateGetDeclaredMethods in java.lang.Class
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|   1808 | getDeclaredMethods        in     ''
|    334 | innerRun . . . . . . . .  in java.util.concurrent.FutureTask$Sync
|    166 | run                       in java.util.concurrent.FutureTask
|   1110 | runWorker . . . . . . . . in java.util.concurrent.ThreadPoolExecutor
|    603 | run                       in java.util.concurrent.ThreadPoolExecutor$Worker
^    722 | run . . . . . . . . . . . in java.lang.Thread
Caused by ClassNotFoundException: org.hibernate.cfg.Configuration
->>  366 | run                       in java.net.URLClassLoader$1
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|    355 | run                       in     ''
|    354 | findClass . . . . . . . . in java.net.URLClassLoader
|    423 | loadClass                 in java.lang.ClassLoader
|    356 | loadClass . . . . . . . . in     ''
|   2442 | privateGetDeclaredMethods in java.lang.Class
|   1808 | getDeclaredMethods . . .  in     ''
|    334 | innerRun                  in java.util.concurrent.FutureTask$Sync
|    166 | run . . . . . . . . . . . in java.util.concurrent.FutureTask
|   1110 | runWorker                 in java.util.concurrent.ThreadPoolExecutor
|    603 | run . . . . . . . . . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    722 | run                       in java.lang.Thread