Safari crashes on start up, Safari crashes on start up

I've read up on people's complaints and how to fix safari but no method is working for me.

Safari worked briefly (using it to reset my secret questions)

But every time I click on safari now I get a blank screen for a second or so before it takes me back to the home screen. If I see what programmes are running (double home button click) safari appears in the bar displaying the apple reset secret questions page (ie the last page I went on with safari)

I've tried resetting safaris settings data/cookies and also resetting using the power and home button with no luck.

I downloaded mercury (Internet browser) before I noticed safari wasn't working also I didn't restore the new iPod from an existing account (just manually signed into iTunes to repurchase my apps individually)

I'm not too fussed that safari isn't working but am that Siri won't work without it. Once I click on a Siri result it obviously tries to open via safari which just chuck me back to the home screen.

Any help is much appreciated