Area portal... Void appearing?

Hey guys..

I am just wondering if anyone could help me
out with something.. i have an area portal in a doorway on my map.. and
for some reason it has a strange void when the door opens...

here is a screenshot

http://www.uditonline.com/web02/cwrightson/base32_portal.jpg

http://www.uditonline.com/web02/cwrightson/base32_portal2.jpg

i pretty followed the basic rules for making an area portal... make a
nodraw brush fill the space..(convert to area_portal) make
another brush that is ur door. (convert to func_door)

if anyone has any suggestions as to why its doing this.. and what i
need to do to fix it that would be awesome! also any suggesitons to
maybe go around using the area portal? b/c without it the section in my
map tends to lag really bad..!

thanks in advance

Sub-Zero

p.s. It didnt seem like someone had this problem happen before...

Of course your area portal is extremely thin, covered in the areaportal
texture, and set with Initial State equal to Closed, right?

Edit: reread the section at http://www.valve-erc.com/srcsdk/Levels/performance_and_visibility.html on areaportals ;-)

thanks bro.. i was following a tutorial i got from hl2world.com.. he
said to make a no draw texture.. anyways i will let u know how or if it
works... compiling now..

It's a bug that often occurs when you tie areaportals to doors.
No-one's sure what it is a actually. Try using a brush rotating-door
rather than the point one.