I just played around with it a little and discovered that graph will disappear if you exit the Dell WLAN Utility from the Exit option in its Tools menu. The connection may still be active, but the graph will be gone. Sounds exactly like what you're describing.
Fixing it is as simple as opening the utility again. Disabling/re-Enabling Wireless from the hardware button should also fix it. As should soft-resetting (but mostly because it reloads that utility during the reboot I'm sure).
If those things still don't fix it, I've got some more drastic suggestions for you that can at least determine if it is a software issue or not.
Fixing the user on the other hand... well, if you can come up with a good solution for that one, patent it, and the rest of us TS geeks will probably make you rich out of despairation
