Are there alternate DNS servers I can use?

Since many connectivity issues are eventually traced to DNS problems, you can add to, or even replace your ISP's nameservers with other public ones.
 
A good alternative is the public DNS services from the Open Root-Server Confederation, which cover some new TLD listings that many other nameservers don't yet include. Below is a list of available ORSC DNS servers you can use (I'd choose ones that are geographically close to you):
 
199.166.28.10 (PS0.NS2.VRX.NET) - Atlanta, Ga
199.166.29.3 (nl.public.rootfix.net) - Nederlands
199.166.31.3 (NS1.QUASAR.NET) - Orlando, FL, USA
204.57.55.100 (NS1.JERKY.NET) - Boston, MA, USA
199.5.157.128 (ASLAN.OPEN-RSC.ORG) - Detroit, MI, USA