problems pidgin with ltsp server

[uwe]

hello everybody,

I have one ltsp 5 server at school and 15 kids. I wanted to introduce
them to using pidgin via the bonjour protokol for chating with each
other.

so I was walking around to each kid - one by one - to set there session
up. after the 10th computer, the kids where not able to connect anymore.
I don't have the exact error message, but if I remember well it reported
a socket/port error. also, rebooting the thin clients did not help.
those who worked also continued to work properly.

I also started pidgin from the terminal to see if there were any further
error messages appearing but there weren't.

has somebody an idea?

thanks,

uwe