Proxying to 2 backends with a if...

[John Doe]

Hi,

Not sure if the mailing list is more popular than the forums, so I ask here 
to...
I setup two servers, each proxying to a different backend, one http and one 
fcgi, and it mostly worked.
Now, I am trying to setup one server that would proxy to the two different 
backends based on the presence of args or a header...
So I merged both configurations, but I have some issues like many configuration 
parameters do not work inside a 'if'.
I moved most outside the if, but I am not sure of the effects.
And the headers don't seem to be proxied to the fcgi backend...
Could some knowledgeable people offer some advice on how to fix my configuration 
file?
You can see the trimed configuration here:
http://forum.nginx.org/read.php?11,166892
Basicaly I want to: "if (args or header) then pass to fcgi, else pass to http 
backend"

Thanks,
JD