I have several datasets in my report all if which refer to the same parameters : UserName, reportstartdate, mpcodes. (A text field, date and a list) I added a new dataset today, cutting and pasting the same parameters, eg. UserName which has ${UserName} as Default Value Expression, exactly the same as all the existng datasets. However, this dataset was not returning any results. So created another one as a test which simply did select $P{reportstartdate} as f1, $P{UserName} as f2 Then added a table for this data set and just get a table with 'null' and 'null'. So it appears the original datasets have the parameters passing through (including a new one I created yesterday) but today all new datasets have parameters coming throough as null. I've spent hours now trying different things to work out what's happening to no avail. There's no difference in the way these parameters are defined. Anyone seen anything like this before? Any ideas? Thanks