I'm using gpg in Windows 7 Enterprise and when I run --list-keys the output to the console is the same 4 keys in a loop for exactly 10 seconds. If I redirect the output to a file gpg --list-keys > keys.txt it writes out all the keys without duplication and terminates immediately.
I do not know how you could reproduce this without my keys. The console output is this same text repeated over and over again:
pub C:\Users\[removed]\AppData\Roaming\gnupg\pubring.gpg --------------------------------------------------- pub [removed] [removed] uid [ unknown] [removed] uid [ unknown] [removed] uid [ unknown] [removed] sub [removed] pub [removed] [removed] uid [removed] pub [removed] [removed] uid [removed] uid [removed] sub [removed] pub dsa1024 2009-01-18 [SC] [expired: 2010-01-13] 4B2D52B0771FA33A1896B699DA5131795788087D uid [ expired] VideoLAN Release Signing Key (2009)
Of course I will remove that VLC key... but for now I've left it in and unmasked it here case it is relevant.