papaborat

Hello, I have a question in regards to clearing my SEVIS record.
I initially came to the USA in 2000 under an H4 visa. I was studying
at the University of Chicao - Illinois (UIC). In 2005 I applied for a
change of status to F1 since I was about to turn 21 and thus would be
independent of my family. My change of F1 was granted in October/
November 2005 and I got my F1 Visa stamped on my passport from the
Toronto Consulate in February 2006.
I became a permanent residence of Canada in February 2006 and thus
applied to the University of Toronto (UFT) in hopes of continuing my
studies there. In June/July 2006 I got accepted at UFT, but still was
undecided on whether to attend UFT or not until end of August 2006. So
in August 2006 I decided to attend UFT instead of UIC and I sent an
email to my international student adviser that I have left the
country. I wanted to visit my friends in the USA last week. At the
Buffalo POE, the US officer told me that I "needed a letter" from UIC
because he said my visa was terminated (which I was not aware of). I
asked him what kind of letter, but he would not elaborate. He said
that if I don't get that "letter", I will have to come into
immigration every time I want to enter the US. Since I am a German
citizen, I don't need a visa to enter the US for 90 days and was
admitted accordingly. However, now I am dumbfounded as to what I need
from my former international students adviser at UIC. Anybody know?
Thanks!