I found ticket number #3202 which seems to describe this problem and I tested the epub supplied by kovidgoyal. (
riki-oh.2.epub)
What I saw was the following:
Cover page was sharp
1st page was text
2nd page did not display at all <-- comic page
3rd page was sharp <-- comic page
So, it can be made to work. Somehow
Addendum: I just tried Adobe Digital Editions 1.7.1.1085 on WinXP and my comics display badly in that too. This might help with tracking down the bug.
Also, this might be related to the bug that had jpegs not displaying correctly. It would be nice if fixing this allowed jpeg pages too