Routing problem (2 RouterOS & load balancing)

Hi,

here my network:

now pc1 can explorer the web usin wan1, wan2 of fw01, and pc02 using fw02.

wan1 and wan2 are load balancing using this schema:
http://wiki.mikrotik.com/wiki/Load_Balancing

but pc1/pc2 cannot ping pc2/pc1 using backbone.

How to do this?

thanks in advance
v.

Are you configured static routes on routers to connect both PC?

*on left router:

ip route add dst-address=192.168.1.0/24 gateway=10.10.20
8.2/20

*on right router:

ip route add dst-address=10.10.0.0/20 gateway=10.10.20
8.1/20

Yes. The problem seems the load balancing. For example:
pinging from pc1 to 10.10.208.2 the pc use wan1 (or wan2) not gateway 10.10.208.1.
I think router needs a mangle entry to bypass odd/even marking. (remeber that I use a persistent load balancing schema like described in http://wiki.mikrotik.com/wiki/Load_Balancing_Persistent )

Thanks in advanced.
v.