TP-Link MR3020 v1.8 - no more access

Hi all,
Since I'm new in here - and not familiar with OpenWrt yet - I'm doing my tests with the original firmware on my new MR3020. It has version v1.8 - got it last week.

Yesterday I upgraded the firmware the latest version (to version "mr3020nv1_en_3_15_2_up_boot(130326).bin" dated March 26. 2013)
I did this as a last resort to solve my connection issue with a wireless Panasonic Network camera.

Since I did this firmware upgrade, I'm not able to access to MR3020 anymore via 192.168.0.254:8080 via the WebGUI. Simply there is no response - also not when pinging.
The MR3020 still works - at least the AP mode still runs fine, I can access the internet using the wireless AP on the MR3020.

Can anyone suggest me what to do - or how to solve?

I tried the failsafe mode - and getting the WPS LED flashing fast - and using 192.168.1.1, however no no response when pinging.(I'm not sure whether failsafe just works with OpenWrt anyway)

Thanks for any help.

John



ADD-ON:

When I'm trying to use WISP mode - I can ping 192.168.0.254 - but still no access via WebGUI :

Johncoffees-MacBook-Air:~ jc$ ping 192.168.0.254
PING 192.168.0.254 (192.168.0.254): 56 data bytes
64 bytes from 192.168.0.254: icmp_seq=0 ttl=64 time=3.860 ms
64 bytes from 192.168.0.254: icmp_seq=1 ttl=64 time=3.114 ms
64 bytes from 192.168.0.254: icmp_seq=2 ttl=64 time=24.235 ms
64 bytes from 192.168.0.254: icmp_seq=3 ttl=64 time=3.040 ms
^Z

Telnet - not sure what command I can set.