I still have the lab building in the original base, but no scientists. However, I get a strange result if I transfer 10 scientists back to the original base (PHALANX HQ):
In research view of original base after transferring 10 scientists back to it:
Laboratory space (used/all) 15/20
Scientists (available/all) 10/10
So 15 of the 20 lab spaces are somehow in use, even though there are no scientists performing research at the base. When I click the "Start Research" button for the Particle Beam Rifle tech in that base, it then assigns 5 scientists to do research (because it thinks there are only 5 free spaces available. It does not freeze, though.
However, if this is an issue (instead of some game rule that I am unfamiliar with), it seems to be a different issue from what is causing the game to lock up. I believe the reason that it locks up when I try to research the Particle Beam Rifle in the DREAMLAND base is because that research item has "0" listed for the number of available scientists, while every other research item shows the correct 30 free scientists. If I click the unassign arrow button for the Particle Beam Rifle, then the number of available scientists for that research item changes to 30 and I can research it without the computer locking up.