Crash when trying to delete terrain (clean install 1.7.1)

Hey all. I just started digging into Torque. I finally have the time after I bought the license two years ago! ;)

Anyway, what happens is that TGEA will crash the moment I try to delete a terrain.
console.log => " (0): Unknown command uninspect."

VC2008 debug:

----

(Unhandled exception at 0x00a6ffe6 in Stronghold_DEBUG.exe: 0xC0000005: Access violation reading location 0xfeeefef0.)

Call Stack: Stronghold_DEBUG.exe!EditTSCtrl::renderMissionArea() Line 606 + 0x3 bytes C++

---

Which is:

if( mActiveTerrain != NULL )
{
GridSquare * gs = mActiveTerrain->findSquare(TerrainBlock::BlockShift, Point2I(0,0));
height = F32(gs->maxHeight) * 0.03125f + 10.f;
}


Now my guess is it tries to do that calculation on the terrain and gets terribly unhappy because it just got deleted. This is a clean TGEA install on a fresh PC (XP SP2, TGEA1.7.1, latest DX9, DXSDK march 2008). I enter the game, hit F11, ALT-C, zoom out, select terrain, (go to create mode, optionally,) press delete, BOOM.

Anybody that can point me in the right direction?

Cheers!