export | import taking a really, really long time

I'm trying to migrate a spam probe database over from an old machine.  The
spamprobe version hasn't changed, (v1.4d is what it reports), but the version of
the database lib has changed, so I can't directly use the old library.  The
problem is that spamprobe export is generating what appears to be an unbounded
amount of output.   It got up to 50G (for a 345M database) before I killed it. 
Now I'm running "spamprobe_old export | spamprobe_new import" so it doesn't fill
up my whole disk, but it's been running all night and the new database is only
33M.   It doesn't appear to have grown at all since I checked it before going to
sleep.

Any ideas? 

Thanks.


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