I've been putting my computer in sleep mode overnight, but when I wake it back up my scroll wheel on the mouse is VERY sluggish. I've tried changing the settings, but it doesn't make a difference. If I reboot, it works fine again. Vista is so crappy. It's like everything wakes up completely but the mouse scroll wheel. Sort of like me in the mornings .........Anyone have any ideas?

Memory leak?
I just had something like that for a week or so but due to different reason. I usually have 2 windows and several tabs open in Firefox. After several hours the browser went sluggish and only rebooting would bring back the normal speed.
Hit ctrl-alt-del and go to task manager > processes. Check the cpu and memory usage of those processes. That might give you a hint what causes the sluggishness.

and check batteries if it's a cordless mouse.

Checked the battery first.

I have everything closed when I put it to sleep.

After a search, I found many forums about this and tried different things, but nothing worked. Simplest solution. I unplug the USB, and plug it back in after I wake it up. It works!

Lagging mouse?
Probably old age.