icmp problem ?

[khaledeshah]

I'm using PIX 515 with some servers behind it & I'm doing static address translation to my servers like this (private address not the correct ones) :

static (inside,outside) 10.0.0.8 netmask 255.255.255.255
static (inside,outside) 43.56.34.2 10.0.0.9 netmask 255.255.255.255
.... and so on

I notice some icmp messages in my log which is logged repeatedly :
Inbound ICMP redirect (code 0, addr 69.0.1.99) 33.56.33.9 > 33.56.33.6 > 10.0.0.6
where 33.56.33.9 is our routers address which pix's default route & 43.56.33.6 is our cache DNS server address & all the addresses in these icmp message are begins with 69.0.x.x
also there is another icmp message :

Inbound ICMP unreachable (code 3) 33.56.37.96 > 33.56.33.6 > 10.0.0.6
what does these mesage mean ?