Problems using synonyms.el

[Frederik]

Hello there!

I've just tried to use synonyms.el from emacswiki but I've encountered 
some problems. This is my setup in .emacs:

(setq synonyms-file "~/_emacsscripts/mthesaur.txt")
(setq synonyms-cache-file "~/_emacsscripts/mthesaur.txt.cache")
(require 'synonyms)

This is the thesaurus file which emacswiki refers to...

The first time I enter M-x synonyms RET, I get
`Building synonyms list for completion.  This will take a few minutes...'
and then I'm able to enter a word. But whatever I enter, I always get
`Badly formatted numeric entry - no period' as return message.

Any hints?

Thanks & regards,
Fred

--
Frederik

freak.fred@gmail.com