I've come to this thread, because I was also trying to set the tabindex on the RadSpell control and it didn't work as expected.
Anyways, what is the purpose of setting the tabindex attribute on the wrapper div of the RadSpell element?
As per the W3C HTML specification
, these are the only elements that support the tabindex property
The following elements support the tabindex attribute:
A, AREA, BUTTON, INPUT, OBJECT, SELECT, and TEXTAREA.
Hopefully you will reconsider and actually fix this problem