How do you check pr, if I may ask that? Or do you mean your pr fluctuates during the update period? And, well, google will stop messing with pr as soon as all those obsessed with it do.
I also had a PR3 and now it is dropped to N/A. I first thought that my website was banned but it is still in google index. Very strange, every link in google webmaster tools disappeared also, but i have like 200 links in yahoo site explorer.
I think he means exactly that. I have the same fluctuations on some sites: PR on some inner pages is changing from n/a to 3 (and back to n/a) - 2-4 times during a month. Normal webmasters don't care. But such situation making work for link exchangers harder
You are lucky that you still have pr0 , they drop me from pr3 to NA ...lol , well its happend some times specially with blogs