What’s new in 2.9.39:
*) fixed scheduler to notice clock changes;
*) fix for miniRouter ethernet tx stop;
*) improved performance of user-manager;
*) some fixes in USB UPS report handling;
*) fixed line power monitor to also work with USB UPS;
*) added workaround for WinBox freeze under latest Wine;
*) added support for Huawei Mobile Connect Model E620 (3G);
*) added support for Novatel Merlin S720 (HSDPA);
*) fixed encrypted link establishment when using nstreme;
What are the specifics of this particular fix?
I’m just about to roll out a wifi network using nstream+wpa2…
It’s replacing a Proxim network btw - no one, not even Proxim themselves, can find a fix for the MP.11a’s constant packet loss 
2.9.39 introduces improvements for the links running Nstreme+encryption, there should not be any problems with Nstreme/Encryption links establishing right now.
If you will run to any problems, then contact support (support@mikrotik.com) with attached support output files and problem descriptions.
I was messing with this today, on a couple of 2.9.38 boxes - it would connect, then disconnect a moment later. Updating to 2.9.39 resolved the problem. Just sort of a confirmation for any searchers…
Tip: stick to fixed key for static links.
Somehow i’ve heard that one before. How does it appear?
Yep, using static keys. Nothing fancy, just making sure the odd wardriver doesn’t get any ideas.
It drops every 16th ping or so and given client feedback, this includes any packet. Seems something administrative/automated within the AP/Router but no one knows what it could be.
after 1,5 year of using rb u solved problem with scheduler 
now it’s working …
thx
Yes, automated like WPA2 is. Stick to wep like aes-ccm keys.
WPA/WPA2 has alot of dependencies.
What problem you had with scheduler?
there was problem with correct date now it’s working ok
scheduler didnt work all that correctly without a battery backed clock