Where did all my tags go?

I have been using the blog feature on BHW as a way to bookmark certain posts, and i've always put tags in to build up my tag cloud.

Now i find that the tag cloud is small and most of the tags have gone, yet they all remain on the posts,
and there are plenty that i can see on the posts that don't show on the cloud, is there anyway i can show them all back on my cloud tag, or is this a forum bug?