doc_z - 8:43 am on Jan 29, 2004 (gmt 0)

My new website PR was raised from PR1 to PR5 in the last PR update, still I haven't noticed any improvement in serps!

Perhaps your site was already a PR5 and just the PR shown in the toolbar was updated.

By the way, recently, there was a similar thread: Will Increased PR Lead to Increased Traffic? [webmasterworld.com] (see especially msg #4).