Try giving explicit width to that label if it is just the label.
If the label is inside a datagrid, then y
ou specify the "variableRowHeight" property of the Datagrid to true and
the datagridcolumn's wordWrap="true"
It's the label on the formItem that contains the grid. I've tried "autoLayout" and setting an explicit labelWidth (together and separately), I would guess that the contained item (a grid in this case) wont change the label properties of the formItem. I"ve also tried making the label a http item and using a line break to no avail. If I could put the label over the grid that might work, but I don't see a placement property for labels.
Worse case I'll have to add a text item before the grid and that will be my last attempt. The problem is the label causes the whole grid to move to the right and takes a lot of realestate I don't want to give up if I can help it.
That seems to do the job. Now I have to study it!