Random bloat in ISO size

Wise, Knowledgeable Knoppix-ers:

I'm following the Customizing HOWTO to create ISOs with general success.

However, sometimes when all I've done is remove a few packages and edit some config files, my ISO magically grows from ~640 MB to ~810 MB. I go in, look around, find nothing, back out, and make the ISO again (takes me ~1.5hrs) it's back down to size.

I'm using shell scripts (mkKNOPPIX and mkISO) for the lengthy command lines that create the ISO. They take no parameters - they were created to avoid typos.

Any ideas?

usually the huge sizes are created by not unmounting /proc. So when you create your iso, /proc is compressed as well.. and if you look in proc there are parts that are huge ( the size of your ram).