You need the new prerm script if you are using wizard-mounter-1.5.4. (else you will get serious trouble uninstalling it)

For using this new script , do the simple steps :
1. open terminal
2. become root
3. execute this command:
    cp /path/where/you/download/the/new/prerm/script /var/lib/dpkg/info/wizard-mounter.prerm
4. You're done!