Here is a thread discussing the same issue:
See post #3 for Jeff's explanation & workaround.
I installed a codec pack for Windows 7 that was supposed to solve the problem.
Ususally not a good idea unless you know exactly what you are doing.
As we are seeing more cameras (mostly lower-end consumer models) adopting this non-standard arrangement, I would guess that when this movement reaches some critical mass, Adobe will retool the code to look for H.264 in an AVI wrapper. Until that time, Jeff Bellune's workaround is probably as good as it gets.
Not sure why someone thought this scheme was a good idea, but it does seem to be gaining some momentum. I speculate that those camera mfgrs. really do not anticipate their customers would want to edit the footage, and soome probably even include some form of NLE with the cameras.