I noticed that sometimes when I run my game some floor tiles would be missing, when I checked they were there and when running it again they appeared ok. I also find that sometimes events run when they shouldn’t regardless of what activation regions have been set up, the two problems may be related.
You can repeat the tiles missing problem if you load up your Abuse demo; run it after loading and it works just fine. Now in the editor press '-' (the minus key) and zoom right out, to help things go even worse scroll left or right so the level is completely off screen. This should make no difference at all as it’s the View element that should decide what’s drawn and if intesecting an activation region only objects in that region should be active, right? Run the game, you'll see half the character is missing as well as lots/all of the level.
Basically what gets drawn or included when running seems to relate to how zoomed in you are within the editor and the position you leave the editor window, this may also be effecting activation regions and overall framerates, especially on low spec systems!?
I'm using the latsest version of GE (v1.3.4).