added a new vlan on one interface, connected a router and from pix, I can ping it
from inside the lan I try to ping the same remote router and fail. I also fail pinging to the vlan interface
ping to the internet is working
From the lan you can only ping the inside interface of the PIX. You cannot ping the far side interface. This is by design not allowed.
What code are you running on the PIX? both the security levels are 100 so you need this command
same-security-traffic permit inter-interface