Panic with shell layering

[Paul De Bra]

Some time ago I got ksh to work on SCO Xenix 2.2 (286) with job control
using the "shell layering" feature. I configured a lot of shell layers,
since the 12 pseudo-consoles each needed 8 layers, plus 8 for each of the
2 serial ports...
It all works pretty well, almost feels like having a BSD system.
(you stop jobs with control-z, play with "bg" and "fg", all just like on
a Berkeley system. i really loved it...)
BUT... every once in a while the kernel panics when switching between
foreground and background. (about once every half hour when i use it...)

Did anybody else experience panics too when using shell layers?
If so, is there a fix, or is it just another feature to be avoided?

Paul.

(by the way, NO i cannot give you this ksh, since it is owned by AT&T)