>I had a working application in VFP 8. I compiled it in VFP 9, and ran it. It came out with an error "Property Value is out of bounds". The error came while executing the line "oGreatWestInBound = CREATEOBJECT([GreatWestInBound])". I tried to revert to VFP 8. Now VFP 8 is unable to open the class "GreatWestInBound" itself. It gives the same error. "GreatWestInBound" is a custom class.
>Finally I cannot compile the application in VFP9, but I can open the class file in VFP 9. I cannot open the class file or compile the application in VFP 8. I am stuck. Can any one tell what could be the reason for this ?

Just a WAG, but there has been a change that will break a class in VFP9. This is where you have a property being set as an object reference in the property list of the class. For example, the following is now broken:

DEFINE CLASS Foo as CUSTOM

    oGreatWestInBound = CREATEOBJECT([GreatWestInBound])

    PROCEDURE Init

    ENDPROC
    blah blah blah
ENDDEFINE

The CREATEOBJECT now has to be moved to the INIT or other appropriate method. So if you are doing this in your class, this would be the reason for the error.