The software that is needed can detect the jail break or root. Even better once rooted on my old android phone,mi ran through the processes to go back to 100% stock and they were still able to detect that it was once rooted. There were some remnants of the rooting process that did not get cleaned up even with removing root and running the stock rom from at&t.
That does not surprise me in the least. Even when I un-rooted the Galaxy Tab, it gave me grief about doing updates; its like somewhere deep in the bowels of the OS there was a switch that got turned on.