Creating shadows of drive objects

There seems to be a problem creating shadows of the drive objects using 
the setting SHADOWID=x:. Therefore I strongly recommend to attach an 
object ID to a drive object before creating a shadow of it. (see also 
Creating drive objects) 

In OS/2 WARP 4 all drive objects have an object ID by default. The format 
for the ID is <WP_DRIVE_x> where x is the drive letter (A, B, ...).