I had the same problem, and found another partial workaround: I emptied the lab with the full data storage of kerbals so it became inoperable. This way, I was able to fill the other of 2 labs on a station where I previously had been unable to. However, not all experiments could be researched. The "big" ones (over 150 Science from Minmus in Minmus orbit) still didn't register, even if I had plenty of free data memory at the time. I was able to fill up the second lab to 494/500 or something like that. Hope this helps someone for whom undocking the lab is not an option.
