dget gpg keys problem when creating backports

[Tadek <finezja@gmail.com>]

First, I' ve never used mailing lists, so I don't know if I do it properly. 

When I created backports according to https://wiki.debian.org/SimpleBackportCreation wiki page, I encountered a problem with the 3rd step:

dget -x http://ftp.de.debian.org/debian/pool/non-free/m/mame/mame_0.148-1.dsc

The dget compliants about gpg key. The hint with using "gpg -k" works for mame package, but it does not work for any other packages I tried (qmmp, htop, smplayer)

I could execute this step only by specifying dget with -c switch.

There is some problem with gpg keys and the dget command. Maybe it should be reported as a bug and the wiki page should be supplemented with a hint about specifiny the -c switch for the dget command?