Are the 2012 tenancy amendments retrospective

Tenancy Deposits

I had a tenancy which ran for 12 months until July 2009 and it was written as an assured tenancy.
At the end of the tenancy - 8 months later the tenants disputed some returns on their deposits and started proceedings claiming damages etc and 3 x deposit penalty .
We defended this as not applicable as it was an assured tenancy but a pre court judgement rules that it will be classed as an AST.
What we would like to know is - will we be liable for a x3 deposit penalty as we have not registered deposit even though it was not required to under our original assured tenancy.
As this case is now being heard in late 2012- will the new law of penalty i.e. - being between 1 and 3 times deposit penalty apply or will it be the older rule of the time of the tenancy ( X3 and no discretion).
Also as we have only just been given the ruling that the tenancy is an AST can we now try to retrospectively protect the deposits even though we have sent settlements out 3 years ago ?
Complicated I know - but appreciate any thoughts on any of the topics this throw up