I went to the States for a half-day shopping trip, and the US border officer stamped my passport upon my entry. However, when I came back, the Canadian border officer did not stamp my passport. So now, my passport doesn't have the last Canadian entry stamp.
Soon I will need to renew my PR card, and I was just wondering if this one missing entry stamp would raise any problem.
It shouldn't, it is common for people who live in Canada to go to the US and return the same day, and it is also common that passports of PRs don't get stamped when entering by land. If you have something to prove you were back in Canada that same day then send it, like a receipt or a snapshot of your bank statement showing activity that day or next day.