When I start the ghci with -package data, I get the following output:

Loading package base ... linking ... done. Loading package haskell98 ... linking ... done. Loading package lang ... linking ... done. Loading package concurrent ... linking ... done. Loading package posix ... linking ... done. Loading package util ... linking ... not found: _rl_funmap_names Abort

I know that I must install the readline library seperately; can anybody tell me how to do this?

It may be that you have the wrong version of the readline library installed. We're chasing a similar problem on SuSE Linux, but I haven't managed to trace the cause yet. Sorry I can't be any more help... Wolfgang - any ideas? Cheers, Simon