Does anyone have a direct link to the Paypal schedule at iStock?  I opened a ticket for payment back on May 12, and 11 days later the ticket is still open and nothing seems to be happening.  I remember the schedule indicating a delay should be expected, but I cannot locate the schedule on iStock to verify if it is time to contact support yet.

Go to the Support page and the link for the payout schedule is under the 'Payment request' option.

you will receive your money on May 25th, if it's not a public holiday in Canada.

You requested payout on Tuesday. Cut-off is monday morning, so you have to wait

Very good, thanks to both of you.  Mo money, mo money...

I know your question has already been answered, but here's a link to the schedule anyways:
http://www.istockphoto.com/docs/PayoutSchedule_2009.pdf

For PayPal you should make your request before 9am MST (= 4pm GST) on Monday to receive it the following Monday. The only exceptions to this in 2009 are Aug 3, Sep 7, and Oct 12, where Monday is a Canadian holiday and you have until 9am on Tuesday to make your request.