Problem with C++ wrapper and gpgme

[Florian Lindner]

Hi!
I use version 0.3.15 of gpgme with gpg 1.2.1 and I try to write a C++ wrapper 
of gpgme. But encrypting is not working, and I can't find out why.
I've uploaded some files:
http://xgm.de/gpg/test.c is a working minimal example. It's working like it 
should.
http://xgm.de/gpg/gpg.cpp
http://xgm.de/gpg/gpg.h
is the C++ library.
http://xgm.de/gpg/main.cpp
is a small program utilising the lib. 
I compile with:

g++ -o gpg.o -c gpg.cpp
g++ -o main.o -c main.cpp
g++ gpg.o main.o -o gpg -lgpgme

I have no idea where is error is. The code is very easy and I've commented the 
places I suspect.
I would really appreciate is someone would have a look at the code and maybe 
can spot the error...
Thanks,
Florian