I wonder if it does not requery only for specific records. I.e. Perhaps the record you have filtered to has a value for GrantSubType that isn't valid based on the GrantType and therefore the Select for the second combo doesn't allow a value to display for GrantSubType. Make sure that the code doesn't work at all when you're filtering. Make sure that the GrantSubType is valid in combination with the GrantType. Also make sure that your filter by form doesn't specify a filter with an invalid GrantType/GrantSubType combination. That could be restricting the display.
Randall J Weers
Membership Vice President
Pacific NorthWest Access Developers Group