If you haven't recently, you might try clearing your browser cache and cookies and see if that helps. Also, there may be an extension in Chrome that is conflicting, if you are running extensions, you might try disabling them one by one and see if that helps.
Thanks Calamondin. It's been OK for about 5 days (after clearing cookies) until today when the same problem recurred. The only Chrome extension I've got is ad-blocker for facebook but I've had that for a year or so without any issues. I don't really want to be clearing cookies on a weekly basis as it's a hassle losing stored passwords etc. I can just live with it for now I guess. Thanks for your help anwyay.
You are welcome. You should be able to clear cookies without losing saved passwords. Look for the check boxes when you are setting up the controls to clear them.