Yes sir, my site has been steady at 4/5 for years and just jumped to 7. I think they made a mistake seeing that I don't have any new ultra strong incoming links to account for the jump and my accumulation rate of lower PR incoming links hasn't changed.
After getting bent over backwards with the Penguin Update and the entire Google algorithm team lining up to have their way with me, page rank has gone up on many pages. Some pages went from 0 - 3. All pages stayed the same or went up. I guess the Google algorithm team enjoyed doing what they do best and are showing a little gratitude.
>> Yes sir, my site has been steady at 4/5 for years and just jumped to 7.
One of the changes Google made to the way they consider links might be playing a part here. If what they did dropped a lot of PR juice off of the link graph, it could mean that the good links you have are worth more than they were before.
On my small hobby forum, all new threads which were started on or before the 26th of April are now either PR2 or PR3. But I don't think it matters much anymore because the forum lost over 50% of g**gle referrals because of Penguin.