[plt-scheme] Installing my .plt package breaks bin/drscheme

When I install my .plt package, the installation routine breaks
plt/bin/drscheme 

I created a plt package using the following command line:

        mzc --collection-plt type-checker.plt type-checker cs173

I then boot drscheme and select "install .plt file" from the "install"
menu. The tail of the installation log mentions that bin/drscheme is
being regenerated:

        setup-plt: Compiling .zos used by type-checker
        setup-plt:   in /home/gmarceau/.plt-scheme/207.1/collects/type-checker/
        setup-plt: Installing MrEd launcher /home/gmarceau/src/plt-exp/bin/drscheme
        setup-plt: Done setting up

After the install, the exec line from bin/drscheme changes from:

        exec "${PLTHOME}/bin/mred"  <lots of X options> '-ZmvqL' 'drscheme.ss' 'drscheme'  ${1+"$@"}

to

        exec "${PLTHOME}/bin/mred"  <lots of X options>  '-qmvL-' 'drscheme.ss' 'type-checker'  ${1+"$@"}

After that, drscheme no longer boots properly.

        gmarceau at catacomb bin $ drscheme 
        open-input-file: cannot open input file:
        "/home/gmarceau/.plt-scheme/208/collects/type-checker/drscheme.ss" (No such file or directory; errno=2)

I am not sure why the installation routine decides to modify
bin/drscheme. I am creating the package wrong?