impossible to sign a key with some expired subkeys

To quote:

When trying to sign this particular key (2BEF0A33), I get the error message that the key is expired. This key is not expired I've been in contact with the key owner, who acknoledged that one ID had indeed been revoqued, but that the main key is still active.

I can confirm this behaviour with this two keys:

pub 4096R/29299233 2011-11-11
Fingerprint=4B84 4C8F B6EB 4194 29F5 EBEC 5764 07A6 2929 9233

pub 1024D/D41F79E4 2009-05-21
Fingerprint=3728 6CC1 DD51 C85E 98AE F01B 1429 7550 D41F 79E4

Both keys have some expired subkeys. But the pub keys isn't expired and in both cases there are at least two subkeys which aren't expired today.

I can confirm one of those at least:

I can confirm this behaviour with this two keys:

pub  4096R/29299233 2011-11-11            
	 Fingerprint=4B84 4C8F B6EB 4194 29F5  EBEC 5764 07A6 2929 9233 

pub  1024D/D41F79E4 2009-05-21            
	 Fingerprint=3728 6CC1 DD51 C85E 98AE  F01B 1429 7550 D41F 79E4 


Both keys have some expired subkeys. But the pub keys isn't expired and
in both cases there are at least two subkeys which aren't expired today.

first reported in Debian BTS #736548.