Shutdown lampoly SNF 2005-03-19 16:36:12: Gap drive problem

[ericp at snf.stanford.edu]

The gap drive seems to stick when it drives to 8.3"
for loading.  Gives error #378.  It keeps trying 
so I manually set the gap to 8" and it is happy
(that is, it's no longer driving, and indicates that it
is at setpoint).  
The gap drives fine everywhere else, but sticks at 8.3, 
which is unfortunately the position needed for loading
and unloading.  There's one wafer in the 
system, presently in the ELL.  Wafer is a machine dummy.