If a table is a member of multiple groups and one checks that table on a system type import, the import button is dithered because multiple items on the page are selected (due to the table not having the same keys as the view on the page.
The validation for dithering should be if the DISTINCT count of the checked tables is <> 1 rather than if the number of records checked <>1.
This originated in version 6.3.1.17502 at Spectrum Brands
A Support ticket was opened and was referred to create an enhancement request - http://support.boaweb.com/hc/en-us/requests/1087
(NOTE: The image below was BEFORE the Import on one item is checked and while the Import button is not yet dithered. If the Import check box is clicked, all lines get the import checkmark and the Import button is then dithered.)