Cordless phone and Wifi conflicts

There is a very strange thing happen between my Wifi connection and cordless phone.
I use D-Link WBR 1310 wireless router and WUA 1340 adapter.
I also have a cordless phone which works on 2.4Ghz. It is Vtech cordless phone.
When I take a phone call with this cordless phone, my wifi connection will be lost.
I also have another cordless phone. It is GE DECT 6.0 TC28223EE3.
It works OK when I use wiless internet connection.
I Googled it and got the answer.

802.11b and 802.11g use various frequency bands within 2.4GHz
802.11a uses various frequency bands within 5.8GHz
Cordless phones currently appear to come in 900MHz, 2.4GHz, or 5.8GHz.
Note that some “5.8GHz” phones will transmit in one direction using 5.8GHz, but in the other direction using 2.4GHz.

The wiless router is working on 802.11g. It is 2.4Ghz. It is same as my 2.4Ghz cordless phone.
So the problem appears.

Most 2.4GHz cordless phones are “spread spectrum’ – in other words, they stomp all over the range of spectra that your 802.11b and 802.11g want to use – and these wifi technologies more cooperatively use one portion of the 2.4GHz spectrum (generally user-selectable).

This paragaph answers my another question. Why cordless phone is OK, but wifi stops working.
So I know the problem, but how to solve it.
I have to use Wifi on 802.11g, because of my Wii and Nintendo DS need it.

I have two ways to solve it.
1) Switch to 900Mhz cordless phone.
2) Try band 11 with 802.11b/g. It tends to conflict less with 2.4GHz phones.
I will try the second way first. If no problem in the next week. I will post here again.
If not, I will put the 2.4G cordless phone away.