I had the same problems with mine. The cure is to get the transmitter as close to the mouse as possible. I had mine plugged into a USB port on the back of my system, and it was just too far way. I got a USB extension cable, and moved the TX to about 1' from the mouse, and now it's rock solid. It's kinda 'ghetto', but I just duct taped it to the back of the re-charging cradle
4-6 days between re-charges is about right, so I wouldn't worry about that. It doesn't take all that long for it to re-charge anyway.
Now, if you are using Setpoint, and
really want to take advantage of all the mouse's features, I'd suggest that you install uberOptions also. It installs on top of setpoint and gives you a lot more programming/profiling options for all the buttons.
uberOptions is Donationware, and you can find it here:
http://www.mstarmetro.net/~rlowens/uberOptions/