Have to reboot Ubuntu 8.04 to get wireless working when changing location or waking from sleep

I have to restart my Inspiron Mini 9 in order to get my wifi connection to work whenever I unsuspend it or change locations. I currently have three locations set up in Network Settings, one for my secured home connection, an unsecured connection at my favorite coffee shop, and a secured connection at school. The only way I can get wireless working at all is if I open Network Settings when I first start the machine (Inspiron Mini 9, Ubuntu 8.04) and select the location. If I open email (Evolution), Firefox, or IM (Pidgin) before opening the Network Settings applet and selecting my location, it won't work. If I suspend the computer, it won't work even after opening Network Settings and re-selecting the location. I also can't use the Log Out or Switch User functions to get it working again; in other words, I have to restart.

This is not a major problem, but it's really freakin' annoying. I'd like to be able to suspend my computer and I almost always want to use wireless, so essentially it means that I can't use the suspend feature.  I've tried sudo ifconfig eth1 down/up which doesn't appear to do a dang thing. Other than that, I have no idea what to do. Any thoughts?