This means that as at January 31 2008 liabilities were exceeding the current assets by $10.4 billion.
As at January 31 2009 liabilities are exceeding the current assets by $6.4 billion.
This gives you a decrease in debt (in liabilities) of $4.0 billion since the previous year (since Jan 31 2008).
Both underlined seem to be correct. 1st sentence tells you more about the decrease in liabilities, 2nd sentence tells gives you more info (is more focused) on the decrease between the current assets and liabilities.
You can interpret this in many ways. It all depends which information is more important for the business. Decrease in liabilities or the gap between assets and liabilities.
I hope this helps. Please note, I am not an english theacher.
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