Intermittent "Java unavailable" errors with yui compressor

[jakedouglas]

I'm deploying to 6 servers using Capistrano and at some point in the process I run a rake task that executes Jammit.package!. Some of the time it works fine, and other times some of the servers report "Jammit Warning: Asset compression disabled -- Java unavailable.". I don't understand where the nondeterminism is coming from, as I can run the deploy process repeatedly with different machines reporting the problem some of the time and working fine some of the time. I also occasionally get "compression failed" (why?).

I'm using jammit 0.6.5 with yui-compressor 0.9.6. Java is definitely installed on all of the machines.

java version "1.6.0_20"
OpenJDK Runtime Environment (IcedTea6 1.9.10) (rhel-1.23.1.9.10.el5_7-x86_64)
OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode)

Any ideas?...