LOGITECH KEYBOARD AND MOUSE FREEZE UP

Hello,
I am on my second Logitech wave wireless keyboard and mouse (the first one I took back bc the Logitech technician told me it must be broken after 2 hrs on the phone). My problem is, if I let my computer sit idle for an hour or so, I come back and nothing works. I have to do a hard reboot to get it to work again. I like the keyboard and really don't want to drive another 30 minutes one way to take it back. I am just hoping someone has a quick fix for me.

My operating system is Vista 64-bit, which seems to cause me a lot of trouble so I'm wondering if it's the problem. I should say that I also have an HP Officejet Pro 8500 that goes off-line after sitting idle for a while, too. Don't know if it's the same problem or not. Again, I've been on the phone and sent several emails back and forth with HP with no solution. It's a hassle rebooting my printer a few times a day when I'm trying to run a business.
Thank you for any help anyone can give me.