I had been having a pretty similar experience with problems connecting or with compatibility to some access points. After not finding any kind of updated driver, I finally went back to dell's driver website and downloaded the windows 7 64-bit version. The automated installer wouldn't work because of an error saying: Error "Setup.rul 60" has occured and Setup cannot continue.
I ran it again to extract the files and then ran the setup.exe with windows 7 compatibility turned on (properties window and the compatibility tab). It worked that time and I've been running that driver for a few days now, and it fixed the problem with that incompatible wireless router. The broadcom driver version that Windows 8 automatically installed was 5.100.245.20. Installing the official Dell DW1520 driver for Windows 7 changed the driver version to 5.100.235.12 (rolling back). I have a feeling that this driver, though made for Windows 7, is going to be more stable than the one made for Windows 8.
Did you happen to try the official dw1520 driver? I'm curious to see if you had a bad experience with it.
Have you had any issues yet with the driver you suggested? That'll be my next try if this dell win7 one doesn't work out.
