if it makes you feel better i have a pinstripe who used to go up the wall to the top of his tank and then try to go across the top until he would start to not be able to hold him self and then just sit there like that testing the lid to see if he could get out. hes in a rack now and is acting "normal" for the last 5 months. and yeah he used to go upside down at times but only when exploring.