Hello, guys. I'm new in the forum, but I play KSP since the version 0.23. Sorry if my English be not so good, I'm Brazilian.
Ok, let's go: I have a little, but annoying issue in the game since version 1.02, simply, when I install a mod (in this case, were Stock Part Revamp, FASA or Tantares, only one of each, because the game crashes when I install every), the atmospheric drag disappears. Yes, is in the stock aerodynamics.
Is like if Kerbin wouldn't have an atmosphere. Apparently, it happens totally when the craft is a Command Pod/Cockpit without a fuel tank and engine, because when I tried the reentry of an Apollo 11 style mission, the craft slowed just when the "service module" was attached to the Mk1-2 Pod, without the tank and engine, the craft continued accelerating to an escape trajectory. The reentry effects are visible, but there is no deceleration. So, I uninstalled the game and deleted the game folders and reinstalled it.
Recently, using the 1.05 (1028) I installed the Dynamic Texture Loader and Outer Planets, and the same issue appeared with OPM, I tested a small craft, and there was no drag.
Curiously, the issue seems to happen just with a mod that uses Module Manager, because it just appeared when I installed OPM.
My notebook has 4 Gb of RAM memory, 32 bit Windows 7, and don't have graphics card. Anyone has the same problem? Or have any idea of why this issue happens?