Your problem is probably power related.
Firstly, make sure your laptop is being powered from the mains when using 'heavy' USB devices.
Secondly, power your Linksys off a USB self-powered hub and not one of those laptop or pocket jobs. It must be capable of over-current support and that means something like a Belkin F5U101 or F5U021 or a Lindy 32889 Smart Hub Pro. The latter is a small, neat, and capable device.