Multiple logon attempts needed

A sufficient answer to this question will be the Technet article number, I misplaced it. But anyway the problem is through gradual expansion of our company I think the network resources are being strained to much, our bandwidth is horrible (14 hubs strewn about a 6500 sq. foot office building – yes, it was against my advice, no I wasn’t the one who designed the network like this). With such a pitiful physical design now it takes the newer employees 5-7 tries before this NT 4.0 network logs themin. Yet, older accounts – employees who’ve been here for 2 years or more, they log in with little to no trouble at all. Why is this? Are my assumptions of a horrible network design on the money?

Thanks.