Password problem after utf8 converting

[mktek]

Hello,

(Sory for my bad English.)

I use SMF 2.0.11. I convert my forum from Turkish character to UTF-8 a few days ago.

Many of our members, whoes names include Turkish (ğüçö) characters, are having password problems now.

If the member's names are similar, the problem gets more complicated.

for example: (ulku/ülkü)

if there is only one member as "ülkü", there is no login problem.

But, if there are both members named "ulku" and "ülkü", the member "ulku" can login forum, but the member "ülkü" has password problems and never login.

I think the problem here:

Code Select Expand

'user_name' => $smcFunc['db_case_sensitive'] ? strtolower($_POST['user']) : $_POST['user'],

How can I solve this problem?