I can't save modifications to paypal config

[Riccardo]

Hi, i have a strange and boring issue. With J!1.5.6 VM 1.1.2 i try to set up paypal payment method but when i click "save" nothing happen, well it waits and waits and waits (you know the sandbox beside the cursor? i mean this wait) but after a minute i get "error loading page" from the browser...with the other payment modules i have no problems...

anyone has a clue? having an e-shop i need paypal, as you can easily imagine

thank you for the help you would give me

Ricky