webchat and mirc connect to the same , altho i think ( but not sure ) uses more than 1 server and lets you random connect ( redirect ) to one of them therefor it could be that not all servers are set to 512 but dont quote me on that.
as i said not realy sure since i dont go there.
also check your mirc settings on flood detection.
ps: i dont see the reason why you would need to send over 512.

Last edited by ik000ike; 10/08/08 06:19 PM.