Why aren't check numbers being matched?

[Carl G. Ponder]

When I import a QFX file from my credit union, gnucash is able to match 
the checks in most but not all cases;
it looks like it is ignoring the check number field and matching the 
quantity and date information instead.
Here is an XML excerpt:

> <STMTTRN>
> <TRNTYPE>CHECK
> <DTPOSTED>20100107000000[-7:MST]
> <TRNAMT>-9045.84
> <CHECKNUM>3608
> <NAME>SH DRAFT
> </STMTTRN>

Is the information being encoded correctly here?
Or is there some setting I have to make in gnucash?
I'm using version 2.2.7 and have had the same problem with earlier versions.

BTW, when I used to use my own spreadsheet, I used two "date" columns 
per transaction, one for the opening date and one for the closing date.
Would y'all consider adding this as an optional feature?