I'm not an expert on this either (where's Skyline when you need him). However this this link is a starting point for you.
http://www.hmrc.gov.uk/manuals/tctmanual/TCTM0 4006.htm
Deep in the HMRC website is a series of manuals that define how the 'rules' shall be interpreted. Look at the second paragraph. What I believed happens is that you can carry-forward or backwards losses made on the property income between different tax years, but you can't transfer profits and losses between earned income and property income/losses - even in the same tax year.
The second para confirms about moving the property income between years. If you dig around in this area of the website you might find something. Otherwise its a call to the HMRC call-centre.