TEXT-S&P cuts 60 ratings on 8 U.S. Alt-A RMBS deals

(The following statement was released by the rating agency)

Jan 15 - Standard & Poor's Ratings Services today lowered its ratings on 60
classes from eight U.S. Alternative-A (Alt-A) residential mortgage-backed
securities (RMBS) transactions from various vintages. Additionally, we affirmed
our ratings on 43 classes from the same transactions and removed 19 ratings
from CreditWatch with negative implications. Of the 19 ratings removed from
CreditWatch, 14 were lowered and five were affirmed (see list).

Standard & Poor's has established loss projections for each Alt-A
transaction rated in 2005, 2006, and 2007 based on a forward-looking default
curve. Our lifetime projected losses for the transactions in this release are
as follows:
Deal Original Loss
name balance (mil. $) projection (%)
American Home Mortgage
Assets Trust 2005-1 462.6 5.92
American Home Mortgage
Assets Trust 2005-1 335.4 3.00
JPMorgan Alternative
Loan Trust 2006-A1 549.1 6.26
JPMorgan Alternative
Loan Trust 2006-A1 323.3 9.95
Nomura Home Equity
Loan Trust 2007-1 600.0 20.42
Nomura Home Equity
Loan Trust 2007-1 423.1 12.27
RALI Series 2006-QS17 537.0 12.00

For deals before 2005, we analyze the delinquency pipelines using roll rate
assumptions and loss severity assumptions to stress the credit enhancement for
each rated class.

For more information on our projected losses for rated Alt-A transactions,
see "S&P Provides Loss Projections For U.S. Alternative-A RMBS Transactions
Issued In 2005," published Oct. 30, 2008, "S&P Revises Projected Losses For
'06-'07 U.S. Alt-A Fixed-Rate And Long-Reset Hybrid RMBS," published Oct. 13,
2008, and "S&P Publishes Revised Projected Losses For '06/'07 U.S. Alt-A
Short-Reset Hybrid, Neg-Am RMBS," published Aug. 20, 2008, which can be found
on RatingsDirect.

The downgrades, affirmations, and CreditWatch resolutions incorporate
projected losses based on the dollar amounts of loans currently in the
delinquency, foreclosure, and real estate owned (REO) pipelines of the affected
transactions. We also incorporated cumulative losses to date in our analysis to
determine ratings outcomes.

The lowered ratings reflect our belief that the amount of credit
enhancement available for the downgraded classes is not sufficient to cover
losses at the previous rating levels. Although cumulative losses were generally
low compared with our projected lifetime losses for the transactions reviewed,
we are projecting an increase in losses due to upward trends in delinquencies
and the current condition of the U.S. housing market. The affirmations reflect
sufficient credit enhancement to support the ratings at their current levels.
Certain senior classes also benefit from senior-support classes that would
provide support to a certain extent before any applicable losses could affect
the super-senior certificates.

The subordination of classes within each structure provides credit support
for the affected transactions. Additionally, some of the structures use
overcollateralization and excess interest to absorb losses and accelerate
payments to certain securityholders.

We monitor these transactions over time to incorporate updated losses and
delinquency pipeline performance to determine whether the applicable credit
enhancement features are sufficient to support the current ratings. We will
continue to monitor these transactions and take additional rating actions as
appropriate.
RATING ACTIONS
American Home Mortgage Assets Trust 2005-1
Series 2005-1

Rating
Class CUSIP To From
1-A-1 02660VAA6 AA AAA
2-A-2-2 02660VAD0 AA AAA
C-B-5 02660VAU2 D CCC
3-M-1 02660VAJ7 BBB AA/Watch Neg
3-M-2 02660VAK4 CCC B+/Watch Neg
3-M-4 02660VAM0 CC CCC
American Home Mortgage Investment Trust 2004-1
Series 2004-1

Rating
Class CUSIP To From
II-M-1 02660TAK9 BBB AA
II-M-2 02660TAL7 B A
IV-M-2 02660TAT0 BB A
II-M-3 02660TAM5 CCC BBB/Watch Neg
IV-M-3 02660TAU7 CCC B
Credit Suisse First Boston Mortgage Securities Corp.
Series 2002-AR2

Rating
Class CUSIP To From
I-B-2 22540VTX0 A A/Watch Neg
II-B 22540VTZ5 BBB BBB/Watch Neg
Impac CMB Trust Series 2003-4
Series 2003-4

Rating
Class CUSIP To From
1-A-1 45254NED5 AA AA/Watch Neg
2-A-1 45254NEF0 AA AA/Watch Neg
3-B-1 45254NEL7 BB BBB+