Still, these nagging problems should not overshadow the dramatic progress that women have made in recent decades.

ECONOMIST: Women and work

Unlike a subscription model, F2P players have no initial buy-in to keep them playing, no nagging guilt over not making use of that monthly fee.

FORBES: As 'World Of Warcraft' Bleeds Subscribers, Free-To-Play Is Already Winning The Future

As if Israel's predicament in a region that may soon become more hostile is not bad enough, two more fears are nagging away.

ECONOMIST: Worried Israel: Encircled by enemies again? | The

What is nagging Europe's political leaders is not the text, which they grumpily signed up to last year, but the difficulty they are having getting it ratified.

ECONOMIST: The European Union

But when it became clear that Sven's men were not going to make life easy for themselves, the nagging fear of a Euro 2000 repeat began to loom large.

BBC: England fans suffer in ignorance

There was just something nagging at the back of my mind that he was not quite the Carl Froch that I have got to know over the past few years.

BBC: man on Froch-watch

But in the back of my mind was a nagging question: Does such transformative leadership produce superior financial results or not?

FORBES: New Research Cites How CEOs Outperform The Market -- Become A 'Transformative CEO'

But nagging questions remain: Why did a man who insists that he is not a collector (and gets miffed when called one) want a museum?

ECONOMIST: Compton Verney and the collector who isn��t