hi,
I to have been having exactly the same problems but would like to somehow keep my livebox without adding an extra wireless boosters, access points, repaters or cabling. I found this on ebay:

eBay.co.uk: Orange/Wanadoo Livebox with External Aerial - BRAND NEW (item 250079892530 end time 10-Feb-07 21:08:00 GMT)

I have emailed the guy and he seems genuine and his feedback is excellent!

I'm torn as to whether to buy it or not