I've had this as well, it started when someone was spamming some ability that i can only assume makes allies invisable, but when the effect wore off i was left running around as a pair of blasters lol.
http://i219.photobucket.com/albums/cc232/Dekkameron/Star%20Wars%20The%20Old%20Republic/Screenshot_2012-03-03_12_23_06_657877.jpg