Hi guys, I hope to be moving to Qatar this September to take up a teaching position. Like yourselves, was very confused whather I would have to pay UK tax. After doing much research (and as wasaloadie and ozzie have mentioned):

1) If you leave the UK and return within 183 days (within a given tax year), you will have to pay tax on earnings abroad.

2) If you leave the UK and stay for more than 183 days (and don't return to the UK for more than 91 days within that tax year) then you pay no tax in the UK.

BUT

To avoid paying tax (2) you have to ensure that you let the dreaded tax man at HMRC know. You will have to complete a P85 to let them know you're going!

I hope this is useful :S