Dude,

I went on June this year. I came here on F1 Fall 2001 and graduated on dec 2005. Since then I have been working on H1. My F1 had already expired when I went to Vancouver. I don't know what kind of F1 visa you have, but I was given those 1 year visa from KTM  and had D/S (duration of stay) written on my I-94. I don't know why your lawyer told you not to go to Vancouver. Did you ever had any status problem in US? I was scared too since I was leaving US after 7 years. The funny thing is I had problem getting canadian visa rather than getting US H1b stamping. Canadian guy was doubtful about me in staying in US for such a long time. Also, you can call the US consulate in Vancouver and ask them too. I think they will charge few dollars for calling them.