pop-up menus sometimes garbled

[BigBit]

I've had my X50V for about a month now, after replacing my X5. I have one nagging problem which I haven't been able to solve.

Every once in a while the pop-up menus in my programs (the ones that pop up from the bottom) appear "squished". The menus only pop-up slightly and the menu text is unreadable. A soft reset takes care of the problem (for a while); eventually, whatever is causing the problem comes back (could be minutes or days later) and it's time for another soft reset.

Any ideas what could be causing this problem?