I have this problem very often.
But this isnt a reason for panic.
Just do the following steps:
1. Open your Explorer
2. Go to your system partition (mostly C

3. Go to the directiory: C:\Documents and Settings (if it called to in Englisch)
4. Then open the folder which is named with your login Name for Windows.
5. Delete the directiory: ".ibot" with all its content.
Thats it.
All Settings and the saved Logins from ibot/kbot are now deleted. But you can restart the bot normally like your first start.
I am doing this at least 3 times a day. But it works.
I dont know whats going wrong.