HBC & media player - network issue.

Hello:

I have an early Wii, with the HBC and BootMii (Boot 2) installed
I use the homebrew channel to play media from my server with samba shares. With MPlayerCe and WiiMC.
This setup has been working for months without fault, the other week, it stopped working overnight, my Wii had not received an update, the symptoms are as follows:

I load the homebrew channel, the homebrew channel connects to the network (flashing icon in bottom right hand corner) - I can now ping the Wii from my server.
I load either MPlayerCe or WiiMC - the network connection is shutdown, the ping from my server stops, the player I loaded says the network is not initialised.
When I exit the player, the homebrew channel initialises the network OK, and the ping starts again.
I have tried the GeexBox player also - this does NOT shutdown the network card, and does work, but I'm afraid it is not suitable for my requirements.
I have tried the following:
Removing IOS202
replacing IOS202
Replacing the player software on my SD card
A different network connection (intitially wired, I changed to wireless for testing)
Running the player from homebrew started from BootMii
None of the above have had any effect whatsoever.
Last night I restored my Wii NAND from a backup taken in January 2010, this was taken before the fault appeared. The restore worked fine - the fault is still there!

I wonder if this could be something to do with an IOS fault? As an afterthought - I remember updating the BBC IPlayer channel around the same time - maybe this has changed an IOS critical to MPlayerCe and WiiMC but not GeexBox...

Can anyone please help?