insserv isdn should be done after successful ISDN setup and not at install 
time. I think, we should only do a insserv if at least one ISDN card was 
configured, we need not to do a 'insserv -r' if all cards are deleted,if 
someone really removed all cards, he should do that with the runlevel editor. 
  

Please attach y2logs. Or, if you did not run yast, reassign the bug. 

Created attachment 46033 [details]
patch for YaST2 ISDN.ycp

A y2log is not useful here, since this feature is not implemented yet. 
The above patch implement it, please include it into the yast network module. 
If done reassign this bug to me. 

Created attachment 46035 [details]
new patch for yast

It should not restore the default set.

OK, I have applied it to yast2-network-2.12.10. 
I read the original report before the discussion on research that prompted it, 
so I did not know exactly what the point was. 

To comment #1:

What's so bad about having YaST also do the "insserv -r" automatically when all
cards got removed?

To me it looks only consistent to have both actions at the same place, so that
after deconfiguring all ISDN cards the system is in the same state as it was
before configuring any.

Created attachment 265626 [details]
proposed patch

This additional patch should also remove isdn (and capisuite if installed), if all controllers were deleted.

Update released for: yast2-network, yast2-network-devel-doc
Products:
openSUSE 11.1 (i586, ppc, x86_64)

Issue is fixed in 11.1.