Tax question - what happens to Roth IRAs in Canada?

If you have a Roth IRA in the US and move back to Canada, will the Canadian government try to tax you on the distribution, or are you covered by international treaty?

2008 tax treaty covers this situation, there are no taxes anymore, it's treated as an RRSP essentially. However you are legally required to declare it to the CRA. I think T1135 is going to be amended to cover this situation but at the moment the instructions say to phone them up and tell them.