The exon detail editor fails to open when Apollo is run under Java 7 JVM, regardless of the operating system. This is due to a change in the behaviour of validateTree, which now requires a treeLock to be held before it is called. The attached patches (made against the current cvs version) ensure a treeLock is obtained prior to calling validateTree, and correct the problem when running under Java 7. I have tested this under both Java 6 & 7, where it seems fine. I've also updated other calls I've foundto validateTree similarly, although I'm not sure when these are encountered at runtime so are untested.