spookey PGP problem... HELP!

[nate at VIS.ColoState.EDU]

OK, I'm running PGP 2.3a on an SGI Indigo R4000 (not that the machine
really matters, but it might help).  My keys were generated with
PGP 2.2 (on teh Mac), and I have since (obviously) upgraded to 2.3 
then to 2.3a.

I just recently started to encrypt a lot of things with my own public
key, and also noticed that the files encrypted with my pubkey were not
necessarily decypherable by my secret key.  I replaced my keyrings 
from backups make a while ago (they're just missing most of my public
keys), and still no luck.  I get the following error:

Pretty Good Privacy 2.3a - Public-key encryption for the masses.
(c) 1990-1993 Philip Zimmermann, Phil's Pretty Good Software. 1 Jul 93
Date: 1993/09/30 05:14 GMT

File is encrypted.  Secret key is required to read it.
Key for user ID: Nathaniel David Sammons <nate at VIS.ColoState.Edu>
1022-bit key, Key ID AE9C65, created 1993/05/24

You need a pass phrase to unlock your RSA secret key.
Enter pass phrase: Pass phrase is good.  Just a moment...
Error: RSA-decrypted block is corrupted.
This may be caused either by corrupted data or by using the wrong RSA key.

For a usage summary, type:  pgp -h
For more detailed help, consult the PGP User's Guide.

What the hell?  Sometimes it will decrypt the file (and sometimes not).
I am very reluctant to issue a key-revocation certificate, since I would
like to avoid this as much as possible, but it's not looking good.

This is really worrying me.  The data I encrypted is not that important,
but it's still a MAJOR problem I am having.

thanks,

-nate

-- 
+--------------------------------------------------------------------
| Nate Sammons   email: nate at VIS.ColoState.Edu
|      Colorado State University Computer Visualization Laboratory
|      Finger nate at monet.VIS.ColoState.Edu for my PGP key
|      #include <std.disclaimer>
|                                    Always remember "Brazil"
+----------------------+