Hello.
In "ip firewall nat" table appears dynamic dstnats from LAN1 public IP address to anothers LANs IP address.
This lines remains in table but I can't see its in "print" command. How these lines grows up and why remains there?
I see dynamic lines in winbox table. For example:

dstnat dstaddress=x.x.x.51 dstport=tcp 2020 toaddress=192.168.3.120
dstnat dstaddress=x.x.x.51 dstport=udp 28963 toaddress=192.168.2.7

All dynamic dst addresses is public address x.x.x.51 for LAN1, but to addresses from another LANs not to 192.168.1.x
Where I see x.x.x.51 is record in route list:
DAC dstaddress=x.x.x.48/28 gateway=ether1-GATEWAY reachable pref.source=x.x.x.51
Maybe preffered source is what appears in dynamic nat?

Thank you for explain.

I'm sorry, I read this a few times and I don't think I understand what you're asking.

Please see picture, I don't understand, why white background lines appears.
More "dst address" is .51 but "to address" is not 192.168.1.x.
And these lines are still there so long as I delete its.

http://wiki.mikrotik.com/wiki/Manual:IP/UPnP

You have UPnP enabled and people are opening dynamic port forwarding holes on your router.

Thank you for explanation Fewi!
It's interesting feature, but it's crazy that it's enabled in default configuration

By default it is disabled.

Ok, I'm not aware I do enable it, but I do too much test settings so it's possible... Thank you.