i just noticed that the packages created during checkinstall
consist of only the doinst.sh and slack-desc files...

the packages do get installed and are listed in pkgtool
but the files are not uninstalled when removing the package

Try to upgrade your checkinstall version from the official slackware package, I had this problem and
the upgrade did fix it.

thanks

i was current with my version
but i went ahead and uninstalled, redownloaded and reinstalled it

seems to be working again
(i can only wonder how many apps i installed
that won't uninstall correctly until i recompile them
and run checkinstall again)

checkinstall doesn't create perfect packages. After installing a package with it you should 'explodepkg' it. You'll find that it doesn't create a proper slack-desc file. These should have exactly 11 lines beginning with the exact same name as the first part of the pkg name. If this is not so then the npackage will not be uninstalled by pkgtool. Just open up slack-desc and correct it. Then delete the original .tgz you just exploded and create the new one. Do installpkg on it and then go in to /var/log/packages and delete the file for the original pkg cretaed by checkinstall (if the name has changed -i.e. if there are two files there for the same pkg.
Same problem sometimes with poorly made pkgs from linuxpackages.net.
If already installed just look at the file for the pkg in /var/log/packages and see if it has anything in the 'Description' section. If not, it's a faulty package and should be fixed as above.

This might be of help in your build script:

CWD=`pwd`

# Household chores for each build script
if [ -f /$CWD/slack-desc ]; then
cat $CWD/slack-desc | sed -e '/^#/ d' -e '/^$/ d' -e '/handy-ruler/ d' \
| cut -d: -f2 | cut -c2- > description-pak
elif [ -f /$CWD/description-pak ]; then
cat $CWD/description-pak > description-pak
fi
if [ -f /$CWD/install-pak ]; then
cat $CWD/install-pak > install-pak
fi
mkdir doc-pak