I made it to start pinentry in a xterm:
~> pinentry-qt
Loading the "qt_" catalog failed for locale QLocale(English, Latin, United States)
Loading the "qt_" catalog failed for locale QLocale(German, Latin, Germany)
Loading the "qtbase_" catalog failed for locale QLocale(German, Latin, Germany)
OK Pleased to meet you
GETPIN
Checking for Caps Lock not possible on unsupported platform: "xcb"
The X11 connection broke (error 1). Did the X11 server die?

So direct afer "GETPIN" the dialog is shown nd X crashes.

Regards
   Klaus
-- 
Klaus Ethgen                                       http://www.ethgen.ch/
pub  4096R/4E20AF1C 2011-05-16            Klaus Ethgen <Klaus@???>
Fingerprint: 85D4 CA42 952C 949B 1753  62B3 79D0 B06F 4E20 AF1C