Thank you Vladimir. Have you lost some of your old KOL source files? If there is anything you cannot find then ask and I shall see if I have a copy.
The version that you posted is from 2003 and does not correctly support the unicode KOLString. I found an old version of KOL (kol287.7z) from mybackups which contains KOLMHToolTip.pas dated from 2006. The contents are the same as the one found here:
http://kolmck.svn.sourceforge.net/viewvc/kolmck/Addons/KOLMHToolTip.pas (just some comments changed). Hopefully you can host that one instead.