I remember being able to detect if a unit was burrowed, with a 1x1 location...I did it once...I just cannot for the life of me find the map I did it in. The method on the wiki says to try and move a unit there, blah blah...and that isn't quite what I want, I would like to just detect if it is burrowed or not...how do you do that? (maybe it's been patched? I don't remember to be honost)

There is no way to just detect the state of a unit being burrowed; there are, however, methods for detecting the effects of burrowing.

The first is what you read on the wiki, detecting whether the area is placeable. The second is 'cloak' detection, which is far more limiting than the former method, because the player with the burrowable unit can own no other units and must set aside computer with "Send all units on Random Suicide Missions" AI script running and the player with the burrowable unit his only enemy.

If you move a unit onto a pixel location and the next trigger detects that unit there, you are burrowed, and can move the unit back to the location. That means it's instant, and no unit is shown. the maplantis dldb has an example map made by (lol) ggg.

Detecting burrow is what that system does. Is there something in particular that prevents you from implementing it?
There may be alternatives. It just depends on what you're trying to do exactly.

I changed it to use seige tanks. The purpose was if a lurker was standing, ally vision for yourself would be enabled, but if it is burrowed, it will turn of vision so you can stack.

1. You don't have to have a visible unit. A P12 dt will suffice.
2. Creating only gives you an error message if the lurker is very closely surrounded by unwalkable terrain. 3x3 tiles should be more than enough room.
3. I can't explain why you would detect a non-air unit in the 1x1 pixel (not tiles!) location when it's just been centered on the unburrowed lurker. There must be a mistake in your triggers or ground units are stacking. Mind posting the triggers or the map?

Make sure you do it in this order:
1. Move location on lurker
2. Move the unit waiting to be moved on top (IE P12 Dark Templar) to that location
3. Detect if the unit (P12 Dark Templar) is in that location and do the appropriate actions associated with lurker being burrowed
4. Move the P12 Dark Templar back to it's waiting area.

Shouldn't there be an EUD to detect burrowed status? It would be shared if there was one; that would be a gift from heaven for a lot of mappers, myself included.

A curse from hell for mac users?

It would work for macs too, if someone found the unitnode offset. Not hard if macs have a program like artmoney.