Problem with Mac Wifi

[#1]

can anybody help please?? i have a mac book pro running OS 10.7.2, wifi used to be fine on it with 10.7.1  Sometimes it will connect to my router other times it connects but sees no internet, other times it will connect and is very slow. Plusnet have supplied me a new Thomson TG585 V8 router, i have re flashed this with the latest firmware, but this has made no difference. I know that there are wifi issues with 10.7.2, i have taken my mac to apple to see if they can find anything wrong with it, but all their tests etc find nothing. They say that probably there is an incompatibility with the lastest OS and the thomson box, plusnet say the boxes are fine with mac's but i should be using WEP encryption instead, even though Apple laughed at this! Has anyone had similar problems or any ideas how to overcome this?  for info PC' phones etc all connect fine, this only started happening when installing 10.7.2,  rollback to 10.7.1 is the obvious answer but not as easy as it sounds!  thanks

[#2]

With the Thomson V8 router, you might want to try setting the wireless mode to "b/g" rather than the default "b/g/n". If you've done that already and it's still problematic, umm... Not sure what to do. With it connecting but no internet, a DHCP server issue? Telling the router to reboot can usually fix DHCP issues.

[#3]

I have seen some problems with long SSID's. Trying changing the SSID to just Plusnet instead of PlusnetWirelessrandomcharacters