I don't know what the lifecycle of a SystemWindow is, but mine
seem to hang around forever.

Try this in a fresh image (don't save afterwards unless you like your
windows rearranged):

Smalltalk garbageCollect.
SystemWindow allSubInstances do: [ :ea | ea openInWorld ].

Wow! You see whatever someone left in your image before it shipped!

Now delete the windows (either by the X button, or by choosing delete
from the windows menu choice).

Repeat the above.

They're still there!

How can I really get rid of them? I'm hoping I don't have to chase
pointers all night...

(2.9a, update 2447).

-- 
Ned Konz
currently: Stanwood, WA
email:     ned at bike-nomad.com
homepage:  http://bike-nomad.com