After I changed domains, I went from a 3 to 0 and have been at 0 for nearly 4 months. Not sure what to do either.
It takes time to get your PR back up, months even. If you have any social media profiles, make sure they show your new URL. Participate in blog carnivals to get new links to your blog. Guest post.
If you're on other people's blog rolls with your old URL, contact them and ask that they use your new URL instead.
Make sure to link to old blog content. For example, if you're posting a blueberry muffin recipe, link to other muffin recipes you have on your blog. If you regularly link to older content on your blog, make sure to go back and fix any links that has your old URL.
Comment on other blogs with your new URL. Even if they use "no follow" tags, at least it lets people know where you are.
Hope that helps and remember that page rank isn't everything.
how unfortunate. I go to your blog often!!! I love it! And I love all the hops you sponsor ;)
I also had this issue. I had a 2, went to my own domain and plummeted to zero. It has been (I believe) since March. I am extremely frustrated. Really, I am more frustrated with Google. They are the owner of the PR checker and they provide absolutely no assistance as to why this is. I am quite annoyed by their lack of customer service. I have a lot of followers and a lot of traffic. I have read and read on this issue and attempted all the fixes. I just gave up on the PR. It ticks me off, though, because I have lost review opportunities because companies look at this.