cannot connect to wifi with 1 Flukso - CAN with the other...

Just restarted tinkering with my 2 FLukso's I bought a long time ago (one has serial nr 10) ;-)
They both had an old firmware ofcourse - v213.
I configured one for my wifi, succeeded, upgrade the firmware via the dashboard, and now it is up & running again.
I'm trying to configure the other the same way (since they are exactly the same), but lo luck.
Sometimes I saw the Flusko trying to associate (on my TP-Link AP), but never succeeding in doing so.
Even tried with another SSID, same result. Reset of the wifi (x second push on the button), same result.
Very strange thing: when I scan for SSIDs (on the 'old' (ie old firmware) Flukso, when I do "iwlist ath0 scan") I cannot see my SSID, although it is broadcasted by my AP (e.g. I can see it on my portable & mobile).
On the NEW Flukso, the "iwlist" does seem to be present, is that correct?
Very strange: when I do "iwconfig ath0" & "ifconfig", I get the following:
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root@flukso-3cb2ea:~# iwconfig ath0
ath0 IEEE 802.11g ESSID:"TELENETHOMESPOT"
Mode:Managed Frequency:2.412 GHz Access Point: 02:53:7C:14:3B:90
Bit Rate:54 Mb/s Tx-Power:19 dBm
RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=26/70 Signal level=-70 dBm Noise level=-96 dBm
Rx invalid nwid:688 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

root@flukso-3cb2ea:~# ifconfig
ath0 Link encap:Ethernet HWaddr A8:40:41:00:00:12
inet addr:10.121.49.4 Bcast:255.255.255.255 Mask:255.255.252.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:138 errors:0 dropped:0 overruns:0 frame:0
TX packets:1180 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:21483 (20.9 KiB) TX bytes:331490 (323.7 KiB)
wifi0 Link encap:UNSPEC HWaddr A8-40-41-00-00-12-00-00-00-00-00-00-00-00-00-00
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:57114 errors:0 dropped:0 overruns:0 frame:10817
TX packets:17705 errors:1260 dropped:16 overruns:0 carrier:0
collisions:0 txqueuelen:195
RX bytes:15774610 (15.0 MiB) TX bytes:1099625 (1.0 MiB)
Interrupt:3 Memory:b0000000-b000ffff
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Apart from the errors on the wifi0 if, it seems that it is connected to a Telenet homespot - altough I defenitely did not configure this...
Anyway, how can I get this 2nd Flukso to connect with my wifi - what can I test/do/...?
thanks a lot !!!