Well I'd try the latest JVM, the current version is 1.6.17 While a long shot, that is an easy and quick thing to do.
If you continue to get this problem on the latest JVM you could attempt to report your problem to Sun. Or look on Sun's forums for solutions.
I'd also run any quick hardware diagnostic tools if you have them. Especially checking your computer memory.
SIGBUS is from your Operating System. So its the interaction between your Hardware, RHEL and Java that's causing the problem.
The problem is not in Alfresco code.