Yes, but that doesnt answer my question about the log.
I have found a Java Out of memory error in the AwareIM log and increased memory yet again. to JBOSS 256M TOMCAT 128 CONFIG 128 in case this is the issue but the save error still exists.
If I delete sections of the document it seemed to save OK but it seemd more about the size of the document
I have not as yet discounted some sort of attibute tag mismatch issue although I have crawled all over the document.
NB. I just tried it again after a reboot / restart and it seemd to save OK, but there is an Integrity problem that just lists the name of the document with no further details. If I click on Edit nothing happenes and I can see any hint in the logs