How to create a small DataMatrix barcode

[zjpgrade]

Hey guys, I have a question on creating DataMatrix barcode with LiveCycle Designer ES4. I need create a DM barcode on a 5mm*5mm size page, which means the barcode's size must be smaller than that. But no matter how I adjust the size, it's always get a yellow lightning sign, saying that 'insufficient space on the form for the pasted content'.  What should I do? Thanks a lot. (Hope my poor english have described the question clearly)