ping problem to radio

hi,
im using routerOS and Zinwell g192 Radio. in my MT i have 3 segment of interface that bridged each other.

segmen 1 : 192.168.1.253
segmen 2 : 192.168.2.253
segmen 3 : 192.168.3.253

i set my access point to bridge mode and the ip was

ip : 192.168.1.254
mask : 255.255.255.0
gateway : 192.168.1.253

the problem was, i cant ping to my radio via winbox. and the strange part is ping loss 95%.. not 100%. sometimes the access point replies.

and when i plug the access point directly to my pc (windows), its running smoothly. i can ping it. ive tried to change eth card but the problem still the same.

Please help me..

Danny