I’m not sure whether I should file this as a bug or not?
Both my PPTP VPN & PPPoE connections disconnect (and reconnect of course) when I set their comment (from both Winbox AND Terminal) with Router OS 4.5 on my RB750. Only the interface that I changed the comment of would reconnect.
I’ve also noticed that when the connection resets, ROS thinks that its transmitting like 1Gbps+ (like an impulse), causing the Traffic sent & received to instantly increase with 4GB with both the Sent & Received!