Profile Manager Login Screen message limit?

I'm trying to use profile manager to set a login screen message. Our message has 360 characters including spaces. The profile manager web page crashed every time I try to save it. If I halve the length of the message it will save and apply. The online documentation I have looked at,http://help.apple.com/profilemanager/mac/2.2/#apd2A822B29-31B2-4DA7-9E3A-6E68DE5 4F5DE doesn't state a maximum character length for the message; is there one? and what is it?

Thanks,

Rebecca