Same here after shibby upgrade to Tomato Firmware 1.28.0000 MIPSR2-092 K26 USB BTgui... no bwmon save happens since my upgrade from 083...
A couple of days ago I upgraded from an older version of the Toastman firmware to v1.28.7497 for VLAN support. Unfortunately my bandwidth monitoring seems to have died somewhere along the way. The realtime and 24hour monitoring works, as does the IP monitoring, but the daily, weekly and monthly bandwidth monitoring just don't update anymore.
So far I've tried switching between RAM/USB and CIFS storage for b/w logs, created a new log backup many times and even wiped and restored everything (clearing NVRAM along the way), but nothing has helped. Any ideas?