DWR

This is a classic 0 vs. null bug which only manifests in environments where timeouts have integer IDs counting from 0. I've observed this on 2.0.5 and none of the issues closed for 2.0.6 seem to address this, so here is a tiny diff:

@@ -1024,7 +1024,7 @@
   }

   // Timeout tidyup
- if (batch.timeoutId) {
+ if (batch.timeoutId != null) {
     clearTimeout(batch.timeoutId);
     delete batch.timeoutId;
   }