Assuming 400K pa, that's 267K for 8 months. Tax on that (excluding MPF 8K) is 13,670 less tax reduction (8K) for a total of 5,670.
The 4 months for this year is 133K (excluding MPF 4K) is $420.
A total for the 08/09 and 09/10 tax years is $6,090 by my calculations.
Six grand isn't much for a year's tax.