IF....AND Formula result

Hi Guys,

I have a formula for IF.. AND that is correct however does not return correct result.

I have used IF(([XXX]="T" AND [YYY]>1000);"0","50")

If I break this formula with only one condition it works however as soon as I use AND, the result always returns "50" even if YYY is greater than 1000.

Anyone who can help would be appreciated.

Thanks