I don't think you can claim a tax credit if it is in an IRA but tax law is very complicated. Check with your broker, if the stock is in an IRA then there should be no withholding. This is automatic with a Canadian broker but is a little complicated if you hold it thru a US broker.
In general its better to hold Canadian stock in a non-IRA account to avoid the hassle.
Canadian "corporations" are not supposed to take withholding tax on their dividends for stock held in US retirement accounts. Canadian trusts still take withholding on such dividends. I believe folks have posted how this depends on the different nature of the dividends. In order to qualify for the exemption the security has to be registered and cleared with the Depository Trust Corporation. Just Energy (JE) has very recently been cleared. I had withholding charged on the most recent dividend from JE which I hold in an IRA, but my brokerage tells me that going forward there will be no more withholding on my IRA JE stock.