NOF (or user account setup?) disables Internet connection

Today I installed NOF on my children's PC (Win 7) and used it to create separate user accounts for each of my kids.  Previously, there was just one account on the PC that everyone used.

Ever since setting up NOF and the individual accounts, the first attempt to access the Internet after switching to a given user's account causes the PC to disconnect from my wireless network.  Within a minute or so, it re-finds the network and re-connects, but the initial disconnect is bothersome. 

Any idea if this is a known issue with NOF, or perhaps a known issue with creating new user accounts?  Thanks in advance for any insights.