We are having this problem.
OUR HARDWARE:
RB2011UiAS with LCD
Router OS 6.11
Routerboard Firmware 3.12
Error we getting:
We run PPPOE authentication over ether1 on all our MikroTik RB's and need to keep rebooting them. Not sure what the problem or issue is, but could be related to the software upgrades or firmware upgrades.
We also keep getting this error on the port running PPPOE "excessive or late collision, link duplex mismatch"