Asp Drop down list problem with IE 11 - encoding characters

Hi,

I have an issue with asp drop down list and IE 11

i have  drop down that contain more that 1500 item with Arabic character encoding, with IE 8,9 10 the drop down work normally and fast

using IE 11 the drop down is so slow when i try to select a value and sometime it's doesn't open 

the problem is in the IE and not in the .net code

Thank you

Regards