Problems with voip and state clashes

[Tim Pushor]

Hi Friends,

I am having real trouble with PF and Asterisk behind a NAT.
The long and short of it is that I'd really like NAT a subset of 
traffic, without putting the connection in the translation table. That 
is, I want to translate the source ip:port on the outbound, but not 
worry about return traffic (since it is handled by a RDR, hence the clash).

Is that possible?

I know this is short on details, but if theres an easy way to do that, I 
don't need to bore you with them ;-)

Thanks a lot,
Tim