Hi, i had same problem with corrupted web interface...

...for me helped fix whitch I found somewhere in german discussion on this forum (I don't understand german, but I tried it and it is working )
Code:
ipkg remove transmission
ipkg install http://demongloom.dyndns.info:81/asus/transmission_2.50-1_mipsel.ipk
Code:
[root@router init.d]$ ipkg remove transmission
Removing package transmission from /opt/...
Successfully terminated.
[root@router init.d]$ ipkg install http://demongloom.dyndns.info:81/asus/transmission_2.50-1_mipsel.ipk
Downloading http://demongloom.dyndns.info:81/asus/transmission_2.50-1_mipsel.ipk
Installing transmission (2.61-1) to /opt/...
Downloading http://ipkg.nslu2-linux.org/feeds/optware/oleg/cross/stable/transmission_2.61-1_mipsel.ipk
Configuring transmission
Successfully terminated.