I'm really not sure... sounds like an issue with spry of some sort. It appears to work fine with firefox on a PC just to add to the confusion. I'd search spry forums on adobe to see if anyone has run into this problem. It is the first I have heard of it here. It doesn't seem like you are doing anything wrong, so the spry code itself must be failing somehow. Are there any errors in the javascript error console regarding that field? Does it still validate on submit of the form and just not onblur?