For the tax year 2008 to 2009 the revenue has introduced new rules for uk persons claiming non residence which most probably know from their contact with the revenue.
For this new tax year the rule has changed for days entering and leaving the uk.Under the old system the day you arrive and the day you leave did not count in your 90 day tally .Now both these dates count as a day in the uk unless you fly out of the uk again before midnight.
Another change that affects 2007/2008 tax returns is that written returns have to be in by 0ct 31st only returns filled out on the internet are eligible for old jan 31st deadline.You may not be able to fill in land and property or residence online this year so revenue reccomend that you download it,fill it in and post it.For 2008/2009 they say you can do it all online