university transfer

Hi, here's my story...

I submitted my student visa application on Jan of 2008 for doing a PhD. My degree starts from Nov of 2007 to Nov of 2010 in the university of nottingham, and I successfully got my visa, which expires on Mar of 2011. However, I left Nottingham on Feb of 2008, and transferred to the university of manchester, where my new course started from April of 2008. I made this decision because I changed my research topic. I found no more interest and I could not continue on the topic I was doing in Nottingham.

I'm currently a second year PhD student in the university of manchester, everything seems fine until I saw "switching to a different sponsor" http://www.ukba.homeoffice.gov.uk/emplo ... g-sponsor/

It says "If a student wants to switch to a new Tier 4 sponsor and their current permission to enter or stay in the United Kingdom is based on an application made before 5 October 2009, they must obtain our permission to switch", but I am a Student in the UK under the immigration rules in place before 31 March 2009. I'm not sure shoud I email home office?

At the time of my trasferring, the student service center in nottingham asked me to fill in a form and suggests me to stay in my home country during the "gap period" of my study. The student service center in manchester required me to send a letter to home office saying what happened. I did as they asked but I did not receive any futher information from home office. I searched the UK border agency websites again and again, however, I cannot find any rules applies on my situation.

Should I email home office? If I don't do anything, will this affect my futher visas?

Thanks in advance for any replies.