Lacking a reply, I tried installing the illimable filters (mentioned in a post re:flac) under wine - the install worked okay but I still could not create a cue file for my flacs. There was an error message for each track and the tracks, once added showed a time of 0:00.00 (indicating, I assume, that they were not added properly).
I've seen a few other codec packs available for download (k-lite, mega-bass) but would really like to hear from someone who has solved this problem on linux/wine...
Thanks.