strange pptp vpn

Hi all

im having a strange issue with PPTP vpn on a mikrotik CRS

i can vpn into the switch fine from my iphone, route traffic over it ok, see other servers, etc…

however when i vpn into the switch from my macbook, i dont seem to get any traffic?

i can see other equipment, the switch, i can get dns replys, ping, etc…

but when i goto a website, it just sits there and never loads???

do you think the is an issue with the mikrotik or maybe my macbook?

i dont seem to have this issue wen i connect my macbook to one of our other CRS at another site, it only seems to be this one?

so maybe a config error with the mikroitk?

regards

Simon