JRException: Cannot shrink cell contents

[ravenheart]

So I'm getting this error from a report which is simply a series of crosstabs. 

It seems to be the column headers that are throwing the exception, and the method for filling the cells - something to do with the width or height it's being told to use being too small?

But I have no idea which cell is at fault. This runs with no problems at all in Jasper Studio and only fails on the server. And when run, everything fits happily in the cells, including when exporting to Excel etc. 

Anyone else encounter this? Googling is useless, it only finds sites which have, for some reason, copy/pasted a bunch of Jasper source code.

Cheers.