Problem p5000etch SNF 2008-08-07 01:24:43: wafer is stuck.

I used several wafers with ch.B. With last wafer, the process stopped with timeout. I went to manual mode and moved the wafer. It looked like that wafer came out of ch.B but I couldn't see it. I left my cassette, please keep the wafer in the box. Thanks,
Yoonjin