Just logged into the LS community site just fine. You only need the original POL ID (ie. ABCD1234) and PW to log in.

I got an SE Account since the beta of FFXIV, a security token since it became available, and moved my POL account payment over to SE account just before the end of the month to receive the Rounsey Wand.

Perhaps the LS beta site was offline for maintenance?