Thanks for your help Austen.
Well what i did was to download jbpm5.1M1 again and reinstall the demo using all the default configurations along with h2. The result was no longer what i described in,
http://community.jboss.org/thread/166124?tstart=30
(so i marked that thread as answered and pointed in here)
I did see the bp model on guvnor oryx designer even after editing, although i did have the trouble mentioned in this thread i.e. oryx erased id and packagename, but once i reentered them (in oryx) could compile and see the process normally. Then if i edit again i would lose the name of the process but then again i reentered it in oryx saved again compiled and all fine.
So i think that oryx has a little bugy behaviour but nothing scary :)