You may check for the features implemented in TDBGrid 8.0 as in the article in link below
Currently we don't have support for version 7 and below of ActiveX controls, so I would suggest you to move to version 8 so as to get full support and functionality of the grid
There is a migration utility as well, that helps you in moving from version 7 to version 8 or TDBGrid
In the link below, it shows the implementation and working of TDBGrid migration utility as mentioned above
Let me know, if anything else!