Whole word search doesn't find the first occurrence

SyntaxEditor search functionality doesn't find the first occurrence in some cases.

Steps to reproduce (SDI Editor Aplication example):
- Type the following text:
$xttt
$xttt
$xttt
- Put cursor at the very beginning (before '$' character)
- Press Ctrl-F and type $xttt in the edit box. Select "match whole word" checkbox. Click Find Next button.

The first occurrence was not found