How to ping from a wlan client to another wlan client

Hello, I have a asus wl-600g router (linux os inside). All is working
fine (each client see the router and can reach the web) but from a
client on the wlan I can't reach others clients in the wlan, so the
router doesn't route.

This is the network:

CLIENT 1 -------> ROUTER - Ping ok
ROUTER --------> CLIENT 1 - Ping ok
CLIENT 2 -------> ROUTER - Ping ok
ROUTER --------> CLIENT 2 - Ping ok

BUT

CLIENT 1 <----------> CLIENT 2 - Ping doesn't reach

Lan config:

default gw: 192.168.1.1 mask: 255.255.255.0

route table on the router:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
213.205.24.97 * 255.255.255.255 UH 0 0
0 ppp_8_35_1
192.168.1.0 * 255.255.255.0 U 0 0
0 br0
default 213.205.24.97 0.0.0.0 UG 0 0
0 ppp_8_35_1

LEGEND: br0=lan and wlan
ppp_8_35_1=wan

What should I do to allow each client to see other wlan clients on the
lan?