gpg error clearing forced signature

[taurus]

Hi list.

k$ gpg --card-status
Application ID ...: D276000124010101000100000BC00000
Version ..........: 1.1
Manufacturer .....: PPC Card Systems
Serial number ....: 00000BC0
...
Signature PIN ....: forced
Max. PIN lengths .: 254 254 254
PIN retry counter : 3 3 3
Signature counter : 0
Signature key ....: [none]
Encryption key....: [none]
Authentication key: [none]
General key info..: [none]
$ gpg --card-edit

Application ID ...: D276000124010101000100000BC00000
Version ..........: 1.1
Manufacturer .....: PPC Card Systems
Serial number ....: 00000BC0
...
Signature PIN ....: forced
Max. PIN lengths .: 254 254 254
PIN retry counter : 3 3 3
Signature counter : 0
Signature key ....: [none]
Encryption key....: [none]
Authentication key: [none]
General key info..: [none]

Command> admin
Admin commands are allowed

Command> generate
Make off-card backup of encryption key? (Y/n) y
gpg: error clearing forced signature PIN flag: Permission denied

Command> quit
$

gpg: error clearing forced signature PIN flag: Permission denied

why this error?

I can change the PIN but not adminPin neither generate a key.


MacOSX 10.5.6
MacPGP2-2.0.10


TIA.

Taur.