If you had firewall software configured to allow access to the networked computers when connected by "crossover" cable, you may have had to enter their IP addresses into its settings. Now that both computers are connecting via a router, which will be allocating the IP addresses, you may have to update your firewall to take account of their new IP addresses.
<<< not both at same time as I am on AOL silver! >>>
As I understand it, AOL Silver only provides one screen name and you cannot have two simultaneous logins with a single screen name. However, I believe that you can have two simultaneous connections to the internet, as with any conventional ISP, provided you don't use the AOL online service, i.e. you can use conventional software such as Internet Explorer, Outlook Express etc., in the second computer, independently from AOL's proprietary service.
<<< Also if I have to run the setup again which option should I choose for 'how does this computer connect to the internet?' Is it via a hub if it is a router? >>>
Personally, I would avoid running the wizard again as you already have the basics set up and are online. Just make sure that you still have the relevant folders set as "shared" in each PC (right click and select Sharing & Security) and that you dont have a firewall blocking access, as mentioned above.