You guys are right on, be sure that you are centered to the anchor point, so that the TRX doesn't pull to one side. And once you are centered, if you continue to fall to one side, you probably need to work on core strength. Side planks, and planks with body saws are going to help you to get stronger! Keep on suspending!
Hope this helps,
Hayley Hollander BS-CPT
Course Instructor Fitness Anywhere, Forum Moderator