Untaxed pension going back 3 years

A relative of mine has just received a notification of underpayment of tax to the tune of approx £1K.  Her company pension scheme, from which she has received a pension of approx £2K a year, went bust and was taken over in March 2010 by the Pension Protection Fund, whose documentation states "on joining the PPF, your records will have been transferred to the tax office dealing with the PPF".  She did not receive any formal notification of amounts payable as pension/compensation.

In December 2011 HMRC have notified her that no tax was ever paid on this pension and the tax due for 2008-2009, 2009-2010 and 2010-2011 is approximately £330 per year.  The pension from the PPF will expire next year and she will only have basic state pension so will be nowhere near the personal allowance.  She certainly does not have £1K available to meet this demand.

Assuming that the amounts received from both the initial pension company and the PPF were received gross of tax (for some unknown reason), then the amounts due would appear correct.  However, for 2008-2010, would A19 be applicable here (2010-11 presumably is still within 12 months so no hope there?).  Certainly she believed that her tax affairs were in order - every source of income she had should have had tax deducted at source.  I'm not sure how to prove HMRC would have had the information from the initial pension fund/PPF though, as this would be a requirement for A19.  Surely this would be a requirement for the pension fund/PPF though - as I mentioned, PPF's literature says that they did it?