Stuck in fan chamber1!

[cajundoc]

I'm at the final stage in Portal... in the chamber with the fan and bright light at the top. Rusty walls. I just used the block to climb in to a little shaft. Entered the fan room and cannot get out. It's like I'm floating above the level requred to get back out.

[OctraBond]

I stuck there too. It is like a not-to-solve glitch. What I do is reloading previous save. You must fire the gun at underneath wall without popping into the chamber.