Port forwarding through second (bridged) router

[Schop]

Sorry, in the first two cases the Airstation was still bridged, the third example was as a router.

No connection further than the Airstation:
            Live (.1.1) - Airs WAN (.1.1  )-Airs LAN (.11.1) - PC (11.2)

Here you have a mistake. The IP for Live and Airs wan port HAVE to be different.

Indeed, just a stupid mistake. It was kinda late when i tried (just before the post)
I'll try again with .2 for the Airstation. Further than that though there are no mistakes: I double checked and those first two situations from my last post are correctly described. (In bridged mode, that is.)

(edit)
Just tried again, the mistake was just in my writing. The Airstation WAN wás in fact set to .1.2 and didn't work as described.

[viking]

If you set up both devices as routers, can you ping the Livebox? What is the output? (TTL, I'm interested in TTL value mostly).
If Airstation is set in bridge mode, what is the response of the Livebox to ping?

[Schop]

Both in router mode gives the following PING results:
Livebox: 1ms, TTL=253
Airstation: >1ms, TTL=64

Results are exactly the same on every try.

What bothers me is that when I tried Google, the TTL is lower than that of the livebox: 243

[viking]

The TTL becomes smaller with every hop (router/gateway) the icmp signal passes.

I don't understand why Livebox replies with TTL 253 (it should be 254) and Airstation with 64 (it should be 255)...
If you connect a computer directly to Livebox, what TTL do you obtain from ping to Livebox?

[Schop]

I was just reading a bit about TTL ( didn't know what it was at first) on Wikipedia but.. As I understand it should start out as 255 (at the PC or at the first hop?) and become one less with each hop as you say. What I do not understand is that it decreases all the way to 64 just to the Livebox, I would expect 253 (or 254?) according to what little I just read. You state it should be 255 at the Livebox which I also don't get :S
Sorry, this is sorta off-topic but I'm just eager to learn 

[viking]

I have to read about TTL, I don't know how to advice you in this moment.

I understand now the 64 value: it is the default value your Airstation router will respond.
I don't think that the TTL [LE] is the problem [/LE] in your situation (I don't think the TTL is the problem for your case). I don't understand though that 253, it should be 254.

[Schop]

The 253 might be because the Airstation is so sophisticated it appears like two hops to the package..
Just thinking loud though.
Weird thing, that TTL. Wikipedia said it was measured in seconds, stored in hex and displayed in decimal... or something like that. Really weird thing to me but never mind.