It's pretty normal to accept usernames in whatever case your user types at the time: indeed, many systems are deliberately case-insensitive with username comparisons ... but if your password is case insensitive then that means you have done something very, very wrong, and that error is normally storing passwords in plain text.
Never store passwords in clear text - it is a major security risk. There is some information on how to do it here:
Password Storage: How to do it.[
^] - the code is C# but it's pretty obvious, and there are online converters if you can't work it out:
C# to VB converter[
^]