Stupidly, I started worrying about chapter lengths (and, to a degree, paragraph lengths) recently, especially after I imported the current draft into yWriter (found via Stumble here and then suggested by Cat, so it must be good).
I like Terry Pratchett's approach to chaptering, but also realise that he can get away with it because, well, he is the big Pterry. As an unpublished writer, one has to conform to certain guidelines to get the foot (leg and body) through the door.
Frank, so far, has 12 chapters, each roughly 8 pages (in Word), except for chapter 2, which is a whopping 3 pages. For me, the chaptering feels right, but self-doubt can be sharp early in the morning. Diana Gabaldon has written a very helpful article about chaptering that set my mind at ease.
Edittorrent has been running a great series on paragraphs that is well worth reading. It has been a great help with the last couple of chapters. This is also a great blog to read for writing tips in general.