when set ppp profile ,idle timeout =00:15:00
when i ADSL connected ,after i don’t use it by time 15m,it don’t disconnet
so i see my ADSL pppoe-client connected mach day’s ..
how about this problem? 
in 2.8.11
this problem happened in 2.8.15 again…
when set time 00:30:00 which don’t disconnected
sorry, nothing about your problem, but another question: what adsl-provider you are connecting to? does it have special characters in the username?
I had see it :http://forum.mikrotik.com/phpbb2/viewtopic.php?t=701
but my problem is can auto disconnected when i set time 00:30:00 or 00:20:00
when i try to set time to 00:00:20 or 00:00:10 it can normal disconnected at idel time come.