This problem was fixed by a Dell engineer replacing the physical wireless card
I have a Vostro 3550 running Windows 7 Pro. It has a Dell Wireless 1702 802.11b/g/n card with an intermittent fault: The error messages that Device manager reports are: and also: These both appear about 80% of the time while trying to use Wifi. A restart of the removes the error message and wifi can sometimes be used as normal for a short period before one of the errors reappears. When booting into a Linux live-cd the error messages also appear with ath9k drivers. I haven't been able to find any help elsewhere, the laptop is however still under warranty and otherwise in good condition.
Dell Wireless 1702 802.11b/g/n - Device Errors