Wireless problem with a Conceptronic CH3WNAS, and more

Using the dsmg600 instructions I installed NetBSD 6.0.1 on my box. Now 
I have a few problems:

1) The wireless connection dies after a few minutes. No errors in any 
logfile or in dmesg, but there is just no traffic anymore. I have found 
that the sequence

ifconfig ral0 list scan
/etc/rc.d/wpa_supplicant restart
/etc/rc.d/dhclient restart

brings back the network, for a few minutes. When I omit the ifconfig 
line, the box also gets an ip address, but it takes far more time, and 
then there is no traffic either.

2) When I shutdown or reboot the box from the commandline, it often 
hangs after spawning

syncing disks... 14 3 done
unmounting file systems... done

to the serial port. Surprisingly when I press the power button, it 
shuts down, so the box is not just stalled. It seemed to help a bit to 
set 'swapoff=NO' in /etc/default/rc.conf

3) Directly after booting there is always a program makemandb running, 
which takes lots (30MB?) memory, causing the box to swap heavily. 
According to google is a sort of man page indexing service. Why does it 
run on each boot? Am I clearing some cache or so.