I am using 6.0rc5 and it was working very well and then I notice some of my ips stopping at a router it shouldnt when I do a traceroute. I logged in the router that the route stopped at and saw this route:
gateway as 0.75.94.144@unknown
Then I started creating a supout and after 45 minutes I got disconnected and could not reconnect. I am currently going to try a reboot. But I wanted to post this issue.
It rebooted by its self because the cpu was maxed out because of the never ending supout.rif. The cpu load before I did supout was around 50-60%. Mikrotik can you fix the strange ospf issue? I can work with you.
jan/02/1970 00:00:15 system,error,critical router was rebooted without proper shut
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own by watchdog timer
I just noticed after the reboot the strange error disappeared.
I am going to upgrade to 6.0rc6 now. I see it came out.
Yeah, got the bug as well.
Reported it to support in rc2, and I keep bugging support to fix it about once every two week for good 2 months now 
The last reply was that it should be fixed in rc6, but I havent tested it with rc6 yet.
its been about a week and I am still online with 6.0rc6.