I think once you go to CM9 through acmeinstaller2 that after that updates are ok to do through clockworkmod...
I actually had a scare today trying to update... For some unknown reason i could not flash updates through acme or CWM... And my android install would only bootloop. Tried all kinds of things but no love. WEBOS worked just fine through..
My fix was to run acmeuninstaller and revert back to a factory reset.(perfect if your sending it back to HP) And then redo the whole acmeinstaller steps. And im back up and running Alpha2
Licenced HVAC TECH: "Without seeing your problem i can only offer suggestions, no warranty is included with my advice"