I will report this to MicroSoft if someone here can reproduce it:

Problem: After saving a grid class which was created using the MemberClass and MemberClassLib properties for columns and headers, the class cannot be reopened and produces an error.

Steps to reporoduce:

[1] Create cgrcolm.prg for the column and header class:

DEFINE CLASS grctest AS Column
       HeaderClass = [grhtest]
       HeaderClassLibrary = [c:\program files\microsoft visual foxpro 9\cgrcolmn.prg]
ENDDEFINE

DEFINE CLASS grhtest AS Header
ENDDEFINE

[2] Create a grid class in a class library
[3] Set the MemberClassLib to the cgrcolmn.prg and the MemberClass to grctest
[4] Set the ColumnCount property to a value greater than 0.
[5] Save and close
[6] Try to reopen the grid class: get ERROR