Have you tried a new battery
today? Heat will fry batteries very quickly. I can snap lots of pics over a two week period in the wintertime in MN on one set of batteries, but can burn through a single set in just one day here in the FL summer.
A few suggestions for cameras, Leica and Panasonic have partnered to build these cameras :
Leica D-LUX 3
Panasonic Lumix DCM-FX30S
The panasonic is very similar to the leica with the exception of the obvious (7.2MP vs. 10 MP) but both have the same Leica optics inside.
We have the Leica here at the office and it is an incredible camera, compact too. I'll be buying one or the other here in the not to distant future.