Before you performed the upgrade did you run...
smcli cleanupd -mva
That command is not included in the documentation but is definetely a very important step that should be included. This cleans out the entire update repository. Now, I'm not sure if the updates live under /opt but I also upgraded from 1.3.3 to 1.3.4 recently at a customer and did not see this issue so I have to believe they do.
If you have never ran this command then note that it could take an extraordinary amount of time to complete so please be patient.
After you clean out the updates, reboot the FSM, and try the update again.
However, if the FSM software cannot even start then I'm not sure this command would be available thus forcing you to rebuild the FSM. If that is the case I am not sure what level of code your Recovery Partition is running but I would advise requesting IBM send you the Recovery media for 1.3.4 so you won't need to do a series of upgrades to your FSM post rebuild. The caveat to that is if you have a recent backup of the FSM on 1.3.3 code, if this is the case then I would request the Recovery Media for 1.3.3 just to be sure your restore will work.
Does that make sense?