I have found another problem in last version of Stage, regarding gripper interface. First of all, I am using Player to control Stage. The gripper is correctly displayed the first time Stage is launched, but when it is closing or opening, it gets all creepy. In Stage 4.1.1-0 it worked fine, but due to some changes in 4.1.1-8 (I think it has something to do with Blockgroup, but I am just guessing), it is behaving that way. Hope this can be fixed soon ;).