ELG-E key requires IDEA cipher?

[Mark B. Elrod]

Hello,

I have an ELG-E key which refuses to work completely with gpg. I can 
encrypt to it but when I try to unencrypt the data I get the following:

gpg: Warning: using insecure memory!
gpg: please see http://www.gnupg.org/faq.html for more information
gpg: protection algorithm 1 (IDEA) is not supported
gpg: the IDEA cipher plugin is not present
gpg: please see http://www.gnupg.org/why-not-idea.html for more information
gpg: encrypted with 2048-bit ELG-E key, ID 46748B13, created 1997-06-04
      "Mark B. Elrod <elrod@vindicia.com>"
gpg: public key decryption failed: unknown cipher algorithm
gpg: decryption failed: secret key not available

I created this key a while back (probably with PGP 5) and would like to 
still use it. My understanding is that EG/DSA keys did not use IDEA. If 
this is the case then why am I getting this error? When I list the info 
on this key here is what I get:

pub  1024D/40C97C30  created: 1997-06-04 expires: never      trust: u/u
sub  2048g/46748B13  created: 1997-06-04 expires: never    

Anyone have any thoughts?

Thanks!
elrod