My DSi can't detect my wifi network (Error 051099-2)

Hi!

As the title says i can't connect my dsi to my wifi network in games (shop and browser works well)

I heard that my router has to have the WEP security instead of WAP but even if i change that my ds still won't detect my network and if i try to configure everything manually an error appears during the connection test (051099-2).

I tried everything, changing channel, 802.11 mode, beacon period, dtim, rts and frag threshold but nothing works, i have absolutely no idea what to do.

This is my router: ZTE ZXV10 W300

Here are some pics of my router configurations:

My router detect my ds like for 3 seconds and then the error appears

Hope you can help me fixing this problem, cya