Have been making a rats style map for a little while now, unusually for me I have encountered very little problems up until now. After every hour or 2 of mapping i do a fast compile to see what it looks like in game.

I recently put a large pipe with a curved top in (the same as in m0gs tut here: http://www.modsonline.com/Tutorials-read-148.html)

It looks great in Radiant, however after compiling the pipes, along with a couple of surrounding brushes are missing.

Never had a problem like this, any idea whats going on? thanks

If you have them in the editor then the problem will be during the compile process. It would more than likely display this error in your log. Post you compile log here and we can take a look.

problem solved now mate, think it was because i had fast-tracked an iwd so my brother could help find the errors. Anyway i took the iwd out of my main folder and its working fine now. Thanks for quick response