Problem connecting to AP (new install)

Hello all.

Brand new hardware.
RB433 L4 v4.5
R52N 802.11 a/b/g/n miniPCI Card
psu 24 V

Have tried so far

Configuration from here
http://wiki.mikrotik.com/wiki/Manual:Making_a_simple_wireless_AP

Error message

00:03:33 wireless,info 00:15:AF:E4:A9:07@wlan1: connected
00:04:18 wireless,info 00:15:AF:E4:A9:07@wlan1: disconnected, received disassoc: sending station leaving (3)


Downgrade to versions 3.3 - not successful
Upgrade to version 4.11 - no diff same error in logs.
Upgrade to version RouterOS 5.0beta6 - no joy either.
After every upgrade/downgrade reset performed and configured from scratch.

Reverted back to 4.5 and dont know what to do.

What are you guys suggesting?

Have you solved?
You use 2GHz or 5GHz band?