Network help.

Ok heres the deal, at work this whole week ive had this major problem getting internet to Bravo Company in the battalion I work in, and I need an outside source to help me think of something new.

Our battalion is all run on a LAN coming right from my office with me being the source of internet for everyone. We have Alpha, Bravo, Charlie and HHC companies plus misc offices in the general area of 3 to 4 blocks. Now the internet runs from my office off a switch to a switch in one of the offices, then it goes into a paragain down to charlie company with a paragain on the recieving end, and into another switch in charlie that goes into bravo company hub at the last spot on the lan. Everyone is online except bravo.
I had tried hubs and switches at bravo as crossover or straightthru cat 5 cables and nothing will work, however if I take out the line from the hub in bravo coming from charlie and plug it directly into a laptop as a straightthru cat 5 it works, but putting it into a hub or switch then running it to the computer it doesnt. I have tried 3 different brand new switches and I just tried a hub. Help me.