Sometimes customers may call and report that their entire Mac computer freezes when they connect to WiFi when using a Comtrend or Smart rg modem.
This is due to a bug in OS X 10.6.8 and earlier, that is resolved in newer versions. It is a well documented issue online.
To fix this problem you can either disabled IPv6 on the Mac in the Network settings. Another option is to disable IPv6 within the modem.