Thanks for your replies!

My level IS way too large (back when we started, I made everything to fit the player model) but 99999 should be enough to touch something when I fly close to it. I even tried the highest number the integer can hold. It can't be too low (it always worked in A7 and with the older shadeC - it might also be shadeC).

The code above was only for testing purposes, that's not the real code that tries to work with mouse_ent. The actual code checks mouse_ent == NULL as far as I remember (I'm not at home right now). Still, if(mouse_ent) is the correct syntax, I believe the only time these don't work is when there's multiple terms, like this:
if(a==b && mouse_ent) //this fails sometimes
but
if(mouse_ent) should work.

Funny thing is: even IF shadeC had an entity that blocked it all, then it should either print the name of that entity, or - if the entity is UNTOUCHABLE then it should print the name of the entities behind it, meaning the level entities that I want to get -.-
But it just sticks to "nil".