if your tablet is plugged in, could be a issue there. I know i have that issue when my computer updates.

Make sure that you only have one pointer device operating at one time. You computer may be getting confused.
I've typically found that wireless devices, Keyboards and mice, have a horrible lag when I use them. I prefer wired devices.
Also, since it's wireless, it could be getting signal interference from another wireless device in the house, someone's bluetooth device or the neighbor's short wave radio. They could be operating on the same frequency.
You might want to check the mouse settings in your computer's control panel, too.

Oh, and LOL, I miss read the title and thought this was about mouth sensitivity problems..

I've dealt with this before on my laptops. Like Eddiebear said your laptop is getting confused because the touchpad and mouse are both on at the some time. You have to disable the touchpad (sometimes as easy as hitting a button on the laptop like mine) until you do that you will have those issues. I had a wireless mouse that was "on the fly" DPI changing so that would increase the sensitivity, downfall it chewed up batteries so I invested in rechargeables before it died. Most mice unless it's a laser mouse have horrible sensitivity. My suggestion is to get a corded one with the on the fly dpi, you can find them on the cheep at newegg mine is by etekcity and I think was only $20 that I use now.

I know how that is pup I got a boxfan to cool down my computer cause the fan died....I hope your problem is a cheaper fix then mine XD