I can see if they are blocking FTP ports, but they are blocking IPSec ports? That's strange...
Depending on the router/firewall you have I would confirm that with Time Warner about the VPN (IPSec or SSL based, depending on your appliance). As another resort you could use something like gotomypc.com or logmein.com to get you access. There is a free version of logmein.com that allows I believe one pc connection, of course to get the full functionality, there is the pro version that gets you all the bells and whistle. Give them a try. They both I believe give you a 30 day trial of their pro software.