I think the A4 just likes to *^$# people off!
when I bought my Triton, the A4 was frozen solid. That was expected though, see pic here:
Picasa Web Albums - ken - triton
I couldn't turn it either direction in gear using the prop, or even with the hand crank in nuetral.
Started to tear it down to see if it was rebuildable, pulled everything off so I could get to the head, and pulled that, poured ATF and mineral spirits etc on the pistons, still couldn't turn it. So I took everything else off and pulled the mounts and got ready to pull it out.
THEN I decided to pull the flywheel cover off, and found a bolt jammed in between the flywheel and cover, looked at that bolt and said NO WAY. Pulled the bolt out and the motor rolled over just as pretty as you please.
After getting all new gaskets and putting the thing back together I dug up a plastic cap to put over the hole in the flywheel cover so I don't have to worry about that happening again.