I've never seen this before - the taskbar along the bottom of my screen is frozen, including the clock. It's been 4:48 for the last ten minutes.
Everything else seems to be working okay, but when I hold the cursor over that bottom section the arrow turns into the hourglass.
I'm going to switch it off manually and see if that fixes it, but has anyone got any ideas what would cause this?

Okay, the problem's disappeared - the clock is reading as it should, everything seems good. It was kind of worrying, though. Even a section of the Bookmarks menu got 'trapped' down there.

Happens to me sometimes. Ctrl+alt+del and logging on and off or restarting usually fixes it. What causes it? I dont know.

So it's not uncommon then.
Happy ending!