Hmmm, weird. What used to take days now takes minutes. They haven't had a PR update since my site went live but I guess it's going to be fairly high if they spider it that frequently.
When your blog/site has fresh contents added regularly, this will attract the spiders to come crawling and the frequency increased. Therefore 10 minutes could be possible when you just added and the spiders are around.
yeah my blog does it very fast, like 2min... I think its the ping issue written above or the sitemap, either way its good