OpenPGP Card: modifying key length fails on Linux

[Stefan Xenon]

Hi!
I use an OpenPGP Card v2 and GnuPG 1.4.10 on both Windows and Linux.

When generating keys on the card, GnuPG is asking at one point which key
length it should use. If I modify the default key length of 2048 to 1024
or 3072 the following error appears:

gpg: sending command `SCD SETATTR' to agent failed: ec=6.88
gpg: error changing size of key 1 to 2048 bits: Allgemeiner Fehler

Because of this, modification of the key length does not work for me on
Linux. But it works on Windows even with the same GnuPG version. After I
modified the default key size on Windows, key generation on the card
succeeds on Linux even with 3072 bit.

Any ideas?

After running into this problem I tried to modify the key length under
Linux with GnuPG v2 but it does not ask me which key length it should
use. Also I did not find any option to specify it explicitly. How to
specify the to be generated key length with GnuPG 2?

Regards
Stefan