Hi Siananigan, nice to see you posting on here, I love your blog!
Sounds like his sleeping patterns have changed and you need to do a bit of retraining. There are a couple of case studies on The Sleepstore's website which sound like you - don't worry, I've got exactly the same problem with my almost 7 month old (eek! 7 months!) so am in the middle of retraining myself. It's specially hard if you have no control over his routine during the day. Anyway
here's the link to the case studies, hope they're helpful.
Good luck!!! And come chat to us in the June or July 08 threads!