check box list control Problem

[Etariq]

hi all
I have this Problem and its driving me crazy;
I have a check box list control witch its lists is created dynamically and
the list box control is set to autopost back
if I check the box index 1 the post back appears but it dose not step into
the selected index changed event of the check box list
in the first time it do the post back but after the first round every thing
goes as it has to suppose to act , and it happens only for the index 1 and
above "2,3,..."

any ideas Pleas help