I have a Microsoft wireless 3500 mouse. I bought it over a year ago, and started actually using it a few months ago. It's been giving me problems from the start. I don't think it's a range issue. My computer tower is right under where my mouse is, and the USB port used by it is in the back of the computer.
Which is right next to the USB port used by my Logitech wireless keyboard, and I don't have nearly as much trouble with that. The mouse that came with the set crapped out on me quickly. It just died. (Like the two Logitech controllers I had for the computer.) But the keyboard has held up well. Only problem with it is that the right arrow key is now broken, but that was more my fault than anything.
My other problem with the Microsoft mouse is the battery life. It seems like I'm always replacing the battery in it.