I just retried my Mars lander orbital rendezvous in the new build (5402) and I still encountered the orbital inflation bug, but only under very specific circumstances. That is to say, when I flew to orbit with my solar panels deployed, everything was fine and my orbit was stable even if I timewarped for days. However, as soon as I tried to retract them my orbit started changing again. I say "tried to retract" because what actually happens when I hit Retract is the panels all turn edge-forward and then don't actually ever fold up, and their right-click PAW permanently shows their state as "retracting", with no subsequent ability to toggle them back to "deployed". Once the orbit is made unstable in this manner, it remains so regardless of timewarp or being focused on a different vessel. Moreover, this happened not just for my lander, but for the orbital mothership as well, with attempted panel retraction immediately inducing the orbital drift, although in that case just one of the four symmetrical panels actually did fold up. Lastly, I should not really call it drift, because as far as I can tell what actually happens is a small, steady prograde impulse that is unrelated to the orientation of the vessel. Anyway, this seems easy enough to work around until there's some kind of actual aerodynamic model to necessitate panel retraction, but unfortunately I don't think this bug can be considered quite dead yet, unless this is just a holdover issue due to the vessels being created in a previous build. I will throw together a brand new vessel this evening and check to see if it still happens with no elements from the last build involved.