There are several issues here to discuss.
1) Lack of tie with Canada. It was a problem before and will be a problem again in the future since you don't live in Canada. It will be easier to develop the tie if you live near the border. Unless you can convince the VO you will move and live in Canada in two years to keep your Canadian PR status.
2) Automatic Visa Revalidation. Actually, according to DOS once you changed your status you do need a new visa stamp to re-enter US. Or you use your expired visa stamp (with valid I94) to re-enter US, then your visa is considered automatically revalidated. However, the IOs at the border are flexible,and that's why many people can come back without problems. That's why you can come back last time.
3) The new visa regulation was not published when you went for F1 visa in March, 2002. After that, if you were rejected for visa you cannot re-enter US even if you have valid I94.
In conclusion, if you cannot come up with a good reason to show your tie with Canada probably you will be rejected again. Then you'll be stuck in Canada. However, if the VO don't ask you this question or you have a good reason for that probably you'll get your visa. I think it's your call to decide what to do next.
1) Lack of tie with Canada. It was a problem before and will be a problem again in the future since you don't live in Canada. It will be easier to develop the tie if you live near the border. Unless you can convince the VO you will move and live in Canada in two years to keep your Canadian PR status.
2) Automatic Visa Revalidation. Actually, according to DOS once you changed your status you do need a new visa stamp to re-enter US. Or you use your expired visa stamp (with valid I94) to re-enter US, then your visa is considered automatically revalidated. However, the IOs at the border are flexible,and that's why many people can come back without problems. That's why you can come back last time.
3) The new visa regulation was not published when you went for F1 visa in March, 2002. After that, if you were rejected for visa you cannot re-enter US even if you have valid I94.
In conclusion, if you cannot come up with a good reason to show your tie with Canada probably you will be rejected again. Then you'll be stuck in Canada. However, if the VO don't ask you this question or you have a good reason for that probably you'll get your visa. I think it's your call to decide what to do next.
