Here's a fun one.
During the first scene upon landing on Nar Shaddaa, I got kicked out of the dialogue tree (it just stopped being in dialogue mode, no input from me).
So Atton, Kreia, Visas and Handmaiden are standing around, the landing pad guy is still off in the distance, he was never triggered.
So I select a party (and here I think is where the crucial development happens) of Atton and Handmaiden.
Then I walk over the the landing pad guy, talk to him, which triggers his normal dialogue.
At the end of it, I am asked to select companions (because, remember, I should have been continuously in dialogue since stepping off the Hawk), again selecting Atton and Handmaiden.
And .... they get cloned, now I have two versions of each of them standing next to me, following, etc.
Anyway, I saved it and exited, so I'll let you know if it goes away on next startup.
UPDATE: Saving and re-loading works just fine, so this doesn't break anything. It's just ... odd.