Kodicom's DDNS service is not good, plain and simple. As far as I understand (and this is from several years ago when they added this), it's all done through Korean servers which are up and down more than ___________ (insert Paris Hilton or similar joke here) and very slow.
Either way, a Linksys router with DynDNS. org support is BY FAR the quickest, easiest and most reliable way to fix this problem without resorting to paying for a static IP address.
I believe the DynDNS solution is better since most people can remember a web address easier than a random set of numbers to punch into IE when using another PC.
Good luck.