[Samba] Master browser problems (I've RTFM;)

[Paladin]

Hi,

I've been having problems having my samba server configured to be the master browser of my network. I've used in smb.conf the flags:

        preferred master = True
	local master = Yes
        domain master = True

and even:

	os level = 255

And still, as soon as I turn on my windows XP pro, it looses it's title as the master browser!
I don't know what else I can try! Did I go over some part of the manual? :/ Hope not...

Thanks,

-- 
Paladin