Wireless keyboard and mouse problem.

[KalebG]

I recently purchased a brand new wireless keyboard and mouse package (the actual item is the Logitech EX110 Desktop, if that even matters). I would have preferred to stick with wired having had problems with wireless in the past, but all the local office supply stores only carried wireless, and I was in need of a keyboard quickly. The pair works great when all I'm doing is chatting, web browsing, etc. But there is a weird kind of interference between the keyboard and mouse at some points. Whenever I hold two or more buttons on the keyboard, the mouse becomes very jumpy in it's position and hard to control. This makes gaming a terrible, frustrating experience, and I enjoy my gaming. I have tried to "re-sync" the mouse and keyboard, just the mouse, and just the keyboard. I have changed the batteries even. Is this just natural for wireless keyboards, or is this a faulty set? I have a 2 year-replacement on it so no big deal if it turns out to be faulty. I would really appreciate any advice or input. Thanks in advance.