[imp] spell checker in imp

[Dirk Ruth]

I have problems with the spell checker when writing mails.
   
  The config/conf.php is configured as follows
   
  $conf['spell']['params']['path'] = '/usr/local/bin';
  $conf['spell']['driver'] = 'aspell';
   
  ... and aspell works in a shell
   
   
  After clicking on spelling in webmail I only get the message every  
time: No spelling errors found. 
   
  How can I go about troubleshooting?
  I am using Horde version 5.2.22 and Webmail (imp) version 6.2.24.  
   
  Dirk