basically, if you've used clip/vertex manip or any other tool apart from the brush tool and the texture tool on those brushes, then it's due to an invalid shape, to fix it, write down all those brush numbers that have errors, go to 'Map / Go To Brush' and type in those numbers, check for errors, and/or delete them and make it again.
it could also be: that you have made that brush into an entity, like a func_wall (ring any bells); you cannot have an entity outside the world, this means no func_walls closing in your map. to fix, highlight the brush(es) and click 'To World' (next to 'To Entity')
failing all that put a big brush around the outside, select it, right click, Hollow (give it a minus number, like -12), and try compiling it when it's in the good ol' "test box", just remember you can't submit maps like this, it's good for checking errors and such.
OR
pt ya map in the vault like he suggested, your problem is probably simple and easy to resolve.