@Ansuel ho trovato perche transmission non si installa, in applications-modal.lp :
post("install_tra
bsmission" );\
mettere :
post("install_tra
nsmission" );\
Dunque nel install script di transmission, si deve aggiungere :
uci set transmission.@transmission[0].enabled=1
uci commit
/etc/init.d/transmission enable
/etc/init.d/transmission start
cosi dopo l'installazione, Transmission funziona.

EDIT:
se non siete sul sugnet di default 192.168.1.x dovete aggiornare in /etc/config/transmission la white list :
option rpc_whitelist '127.0.0.1,192.168.8.*'
perche sono sul subnet 192.168.8.x
EDIT2:
il link è :
http://ip_del_router:9091/EDIT3:
dopo aver disinstallato Transmission, il package transmission-daemon è sempre installato, non sarrebe meglio mettere 2 line per disinstallare ?
opkg remove transmission-web
opkg remove transmission-daemon
Edit 4:
when i stop nginx and restart it, access to the transmission webui doesn't work anymore, i get this error message in the browser :
409: Conflict
Your request had an invalid session-id header.
To fix this, follow these steps:
1. When reading a response, get its X-Transmission-Session-Id header and remember it
2. Add the updated header to your outgoing requests
3. When you get this 409 error message, resend your request with the updated header
This requirement has been added to help prevent CSRF attacks.
X-Transmission-Session-Id: b6EJ3c348WPIqaqVJr5xxWW68WqfGCUqqsOxXdA1e8TT3HwW