Forum Moderators: open
Welcome to WebmasterWorld [webmasterworld.com]!
Don't worry about it. Incoming links can add PR, not take it away. The only "problem" with incoming links less that PR4 is that they do not show in Google's display of your backlinks. If you cannot get an incoming link from a PR5 site, then 100 incoming links from PR4's may have the same results.
Also, remember that PR affects ranking in searchresults only where all other factors are equal. A well-targeted PR3 page can easily beat a much highere-PR page if it is a better match for what the searcher entered as search terms.
HTH,
Jim