problem with exporting subkeys

[JanuszA.Urbanowicz]

Today I tried to export a secret subkey from one GPG installation to another
(both run Debian Potato):

Subshell:alex@FUCKUP:[~]:7:0:> gpg -a --export-secret-subkeys > subk

the 'subk' file bot transferred to another machine, then I ran:

Subshell:alex@syjon:[~]:100:> gpg subk
gpg: NOTE: THIS IS A DEVELOPMENT VERSION!
gpg: It is only intended for test purposes and should NOT be
gpg: used in a production environment or with production keys!
gpg: Ostrze=BFenie: u=BFywana pami=EA=E6 nie jest pami=EAci=B1 bezpieczn=B1!

[nothing?]

Subshell:alex@syjon:[~]:101:> pgpv subk
Opening file "Temporary PGP Keyfile" type binary.
Copying key file to "/tmp/ptmpUWCevZ", running pgpk to process it...

pgpk -a /tmp/ptmpUWCevZ

Adding keys:

Key ring: '/tmp/ptmpUWCevZ'
Type Bits KeyID      Created    Expires    Algorithm       Use
sec  1024 0x21939169 1997-09-24 ---------- DSS             Sign & Encrypt
sub  2048 0xA2E48564 1997-09-24 2000-12-30 Diffie-Hellman
sub  2048 0x78174410 2000-03-14 ---------- Diffie-Hellman
sub  1024 0x7E2E803D 2001-06-28 2003-12-31 Diffie-Hellman
uid  Janusz A. Urbanowicz <alex@eris.phys.uni.torun.pl>
uid  Janusz A. Urbanowicz <alex@bofh.org.pl>
uid  Janusz A. Urbanowicz <alex@bofh.torun.pl>
uid  Janusz A. Urbanowicz (notebook) <alex@sword>
uid  Janusz A. Urbanowicz (ICM) <alex@icm.edu.pl>
uid  Janusz A. Urbanowicz (Jabber ID) <stomil@jabber.org>

sec  1024 0x27C81BC9 1994-01-05 ---------- RSA             Sign & Encrypt
uid  Janusz A. Urbanowicz <flatline@mat.uni.torun.pl>
uid  Janusz A. Urbanowicz <flatline@ipx1.mat.uni.torun.pl>
uid  Janusz A. Urbanowicz (BOFH) <alex@bofh.org.pl>

2 matching keys found

First question: why ALL my secret keys in the packet? I supposed only
subkeys would go there.

Second question: why GPG chokes on it?

Subshell:alex@syjon:[~]:106:> gpg --import subk
gpg: NOTE: THIS IS A DEVELOPMENT VERSION!
gpg: It is only intended for test purposes and should NOT be
gpg: used in a production environment or with production keys!
gpg: Warning: using insecure memory!
gpg: read_block: read error: invalid packet
gpg: import from `subk' failed: invalid keyring
gpg: Total number processed: 0

Alex
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