Logitech Wireless Keyboard & WLM Problem

I have a Dell XPS 8300 and a Logitech MK710 wireless keyboard/mouse combo. the keyboard was an option when configuring my computer on Dell's website. I've had it for a year and from the beginning, I've had problems in WLM with scrolling panes being jumpy or jittery, text showing up on the screen is not synchronized (a delay in seeing what I'm typing) and if I put my cursor on the WLM shortcut in the taskbar to choose which window in WLM screen I want to access, many times one of the preview screens will be black. After I open it, it will correct it's self.
First keyboard needed replaced under warranty. Replacing the keyboard (with another MK710), problem remained. At this time I didn't know what the problem was. I did try a wired mouse but that made no difference. Today, I'm using a wired Dell keyboard. SO FAR, I've had NO problems! Everything is working as it should. I'm not ready to call it just yet and say the wireless keyboard was the problem, but I would have experienced the glitches by now using the wireless keyboard.

Is it a coincidence or could the wireless Logitech keyboard actually be a problem with WLM v2011 (Build 15.4.3555.0308). Keyboard driver is up to date.
Thanks,
Monica

Update: After 10+ hours using this wired keyboard, I'm convinced the wireless Logitech keyboard (remember, I've had two and they both were problematic) has been my WLM problem. Any ideas? I don't understand how the keyboard could cause issues in WLM. Has anyone heard of this? Google hasn't (or I can't come up with the right combination of words).