http://bugs.winehq.org/show_bug.cgi?id=9408
--- Comment #13 from Jeremy White jwhite@codeweavers.com 2009-02-26 07:36:50 --- I managed to work around the 4.23 bug, thanks, and play with this a bit myself.
Here is what I've found: the 'select a source...' menu choice seems to just use the twain get default call (instead of letting you pick a source, which is what I would expect. I find it puzzling.) That means it will use the first scanner found, and so it will find a gphoto scanner, if any. So I found it necessary to remove gphoto.ds in order to get it to go to a sane scanner.
After I did that, I was able to do a scan, and I got Wine's scan dialog box. Switching it to color got me a successful scan. (Although it's hard to tell that's what happened, as the scanner just returns a black picture; you can tell, because the i_view UI changes shape). I can't do a gray scale scan (which is a known limitation, but at least now I get the fixme telling me that).
Does that match?