Is this a known problem or unique to me?
Have I missed something in the installation?
This happens a lot in windows 7 especially if theres a loose USB plug on your PC.
After updating my windows 7 Ihave seen substantial repair now I dont encounter such problems a lot but still they happen rarely but they will keep on happening as the ATmega8u2/16u2 is loaded with a firmware that does all this communication its not essentially everything hardware functionality.
The best is the FT232RL sporting Arduino Deumilanove I have next to no problems with it as it employs a FT232RL serial to ttl chip and vice versa hardware support.