Commented Unassigned: Ajax Combo box control issue with IE11 and Fire Fox [27762]

I m having Ajax combobox control used in VS 2013 web application and its working fine in Chrome but autocomplete mode is not working in IE11 and FireFox and it doesn't allow to type in the dropdown and it doesn't get filtered at all.
Please advise if there are any workarounds for this issue.

Thanks
Comments: Is there a work around?