RB3011 is still exhibiting flapping issues on 6.48.3, I put my initial information in the following post:
http://forum.mikrotik.com/t/rb3011-port-flopping-bad-design/114846/1
Problem seems to have started around 60 days of uptime and then reoccurring nightly during a scheduled nightly snapshot of backup transfers where it’ll flap between 6 and 8 times - all devices on both switch chips are negotiated at 1Gbit so there is no 100/1000 mixes, similar flapping counts seen on all ports on switch 1, no flapping events on switch 2 (but there is only one link on that port which is the link to the internet fibre box - negotiated at 1000, full duplex)
Edit: after reviewing interface up/downs it would appear some occurrence can be over 20 within the hour, others only 6 during full speed file transfers. as stated in other posts the network hardware that theyre connected to is different on adjacent ports but showing similar and in some cases identical link drop counts.