manually purge .deb file

[erchamion.beren@gmail.com]

hello, i compiled firefox from source and made a .deb file via alien. while 
installing the deb file i hit cancel, somehow i cannot remove this file, 
dpkg , aptitute or apt-get says that my firefox packet should be removed but 
no file related to my firefox packet,
how can i completely purge it ?
the log:

0 packages upgraded, 29 newly installed, 0 to remove and 0 not upgraded.
Need to get 0B of archives. After unpacking 37.3MB will be used.
Do you want to continue? [Y/n/?] y
Writing extended state information... Error!
E: I wasn't able to locate a file for the firefox-1.5.en-us.linux package. 
This might mean you need to manually fix this package. (due to missing arch)
E: Couldn't lock list directory..are you root?

Thanks.