About an hour ago my IP changed for only the 3rd time in probably over 3 years with my ISP while using DHCP. For some reason DNS isn't working very well. basically, command line utilities as far as I can tell are resolving everything fine, but GUI's such as IE and xchat have been having a hard time. I sort of found a pattern while looking at some stuff with nslookup. The domain names which seem to not want to resolve are the ones that are aliases. For example, www.l.google.com resolves fine but www.google.com won't resolve. nslookup lists www.google.com as an alias for www.l.google.com. Another example is this site. antionline.com resolves fine, but www.antionline.com won't resolve. I had to save the front page to my computer and edit the action in the form to login. My questions are as follows:

Is this something that will fix itself over time?
If not, is it a problem on my end or my ISP's end?
If it's on my ISP's end, should I contact them?

I don't see how it could be on my end as I never had problems with my router (just a soho d-link with a built-in dns server) before and I haven't changed anything on it.

Basically, what would you do in this annoying situation?