[Serusers] duplicate invite

[Ser Users]

hello,

I am using ser 0.8.14 with tm and acc modules and I have multiple 
"failure_route" blocks.

when the call setup takes longer the client sends a second invite with 
the same call-id which I see in accounting that is not logged (it is 
absorbed by tm module as a retransmission I think) everything is OK, but

the main route block is still executed for the retransmitted invite. is 
there a way I can configure ser not to execute the main routing block 
for the retransmitted invite ?

I have tried:
---------------------------------------
if (!t_newtran()) { break; }
OR
if(t_lookup_request) { break; }
---------------------------------------
in the main route block but I get: "WARNING: script writer didn't 
release transaction" and a "server error" at client side.

is 0.8.14 the latest "stable" version of ser ?

thanks,
Razvan Radu