Bogofilter won't learn anymore

[Alexander Borghgraef]

 I have this very annoying problem. Until recently, bogofilter
worked very well for me. But now there seems to be a problem:
bogofilter -s doesn't do anything anymore. Whether it's a large 
body of spam, or a single mail, the program just hangs. I use
version 0.15.7, goodlist.db is 15M large, spamlist.db is 5M.
Any ideas? 

-- 
Alexander Borghgraef
Vakgroep Telecommunicatie en Informatieverwerking Tel: +32-(0)9-264 34 16
Universiteit Gent                                 Fax: +32-(0)9-264 42 95
St-Pietersnieuwstraat 41, B-9000 Gent, Belgium    email: ab at telin.UGent.be