Thank you both for testing And for the quick reply.
Alpha1 should be fine to run with the same data dir, however alpha2 has had an upgrade to leveldb and as such would need to resync from scratch with an empty datadir (keep wallet.dat of course)

With that said, I have also noticed bugs in Alpha2 that kick in around block 350k while syncing. So, at this point Alpha1 is the one to test. I will remove Alpha2, and rollback the code updates untill I know which one caused the issues.