Casio QV-R41, Ixus430 Nikon cp 4200

[Crasel]

Hi! I am looking for a digital camera to substitute my classic Olympus mu-I which has lasted for several years working nicely.

I've been reading posts, reviews and specifications but at last I am a bit overhelmed with information. Anyway, I have selected three cameras to decide among them:

Casio QV-R41
Canon Ixus430
Nikon cp 4200

The Casio is the cheapest one but uses AA-type rechargeable cells. Is this a disadvantatge? The Canon is much heavier and more expensive. The nikon looks great but I've read a lot of posts complaining about computer connectivity problems.

So I need help, mostly because I am beginning to change my mind and taking other possibilities in consideration like:

Konica Minolta Dimâge G500
Casio Exilim series.

And besides, is the difference between 3 and 4 Mpix worth the difference in price?
I did not consider other brands because of the ISO offered (like KONIKA Optio with ISO up to 200) is this a reason enough?

Well, I apologize for the long post, and the basic questions (I think all begginers have had the same kind of doubts). I'll be very grateful to anyone sharing his knowledge and lighting me a little on my decision.

Thanks a lot!!

Crasel