The problem with username: "this profile does not exist"

Hi. Joomla 2.5.9 + CB 1.9
If in user login there is a "_" (ex. Jhon_Dow) when viewing the user profile ((/component/comprofiler/userprofile/Jhon_Dow.html) sef or non-sef doesn't matter) shows "this profile does not exist or is no longer available". If _ remove it's all ok.
But with _ user all fine. He may entered on site, and see his profile (/profile.html).

HiopsNerevar wrote: Hi. Joomla 2.5.9 + CB 1.9
If in user login there is a "_" (ex. Jhon_Dow) when viewing the user profile ((/component/comprofiler/userprofile/Jhon_Dow.html) sef or non-sef doesn't matter) shows "this profile does not exist or is no longer available". If _ remove it's all ok.
But with _ user all fine. He may entered on site, and see his profile (/profile.html).

are you sure that the issue also in present with non sefed links?

Hmmm. Strange. If i disable sef, then link: (index.php?option=com_comprofiler&task=userProfile&user=42&Itemid=524)
works good. But in my gallery I use (if sef disable): (index.php?option=com_comprofiler&task=userProfile&user=john_dow) or any else (index.php?option=com_comprofiler&task=userProfile&user=johndow) and they not work. But, this is likely my fault and I set incorrect link to rewrite.

But on site i use sef, and hoped the link will be (/component/comprofiler/userprofile/Jhon_Dow.html) (or (menuname)/userprofile/Jhon_Dow.html)

Any idea why this is happening?