BlackBerry Pearl 8120

I cannot get the wifi feature to work properly. I can connect to my wifi connection but when I do, it breaks my internet connection, as it, I have to unplug my router for 10 secs and plug it back in for it to work at again. So I had to turn off wifi on the phone so it wouldn't mess up my internet connection anymore. Then when I do get it working again, it won't use that connection, always uses EDGE. I'll try some hot spots at work tomorrow but I am having no luck with the wifi feature at all.