With just under 19 per cent of the original balance outstanding, S&P has raised its ratings on eight classes of subprime and non-conforming mortgage-backed securities issued by Sapphire VII Series 2005-1E Trust and affirmed the 'AAA' ratings on the Class A1 and A2 notes. The Class MA1 and MA2 are now also rated 'AAA'. The ratings affirmation and upgrades reflect the build-up of credit support sufficient to withstand the estimated losses commensurate with the revised rating levels. There are no outstanding charge-offs to the remaining notes and all losses have been covered by excess spread. Annualised prepayment rates have been quite volatile, ranging from a high of around 50 per cent in September 2008, to around 15 per cent currently. Further volatility in both arrears and prepayment rates is expected as the pool balance diminishes.S&P also took various rating actions on subprime and non-conforming RMBS issued by Sapphire VIII Series 2005-2. The ratings on the Class MA and MZ notes were raised to 'AAA' and 'A+' from 'AA' and 'A' respectively, and the ratings on the Class CA and BZ were lowered to 'CCC+' and 'BB-' from 'B-' and 'BB', respectively. Ratings on the remaining five classes of notes were affirmed.S&P is maintaining its CreditWatch with positive implications on the Class C, D, M, E and F RMBS issued by Mobius NCM-04 Trust and added the rating on the Class B notes to the CreditWatch. The initial CreditWatch placements followed a review of a restructure by the noteholders, concerning the trust's lenders' mortgage insurance deposit account and reserve account. The secured creditors passed a resolution in March to accept the restructure as proposed. Documentation has been finalized and executed, and A$7 million is to be deposited into the reserve account, which can be used to cover losses on any loans in the trust. S&P will resolve the CreditWatch after confirming that the funds have been deposited into the reserve account.Following a review of the subprime and non-conforming RMBS issued by Mobius NCM-03 Trust, S&P affirmed its ratings on the Class B, C, D and E notes. The current portfolio balance of A$57 million is about 10 per cent of its original balance and comprises 64 per cent of low-documentation or no-documentation loans. About 54 per cent of loans have a loan-to-value ratio exceeding 80 per cent, and over 32 per cent have loan sizes exceeding A$800,000.The outcome of a similar review on the Interstar Titanium Series 2006-1 Trust was the raising of ratings on the Class B and C tranches to 'AAA' and 'A' from 'A+' and 'BBB' respectively, and affirmation of the rating assigned to three other tranches. Approximately A$57 million remains outstanding on the portfolio of subprime and non-conforming residential mortgages.