I have been struggling with a similar problem myself. Downstairs laptop no problems - upstairs identical laptop (I bought them as a pair about 6 months ago) drops single at various times. Tried installing a booster - no difference. Tried replacing hub with more up-to-date version - still a problem. Tried re-installing Windows 7 - no change. Will now try swapping laptops over Xmas to see if that improves matters, but I suspect that its the different routes the signal has to travel and the walls the signal has to pass through - sometimes you may have to move the laptop to solve the problem!!