Firstly the line as suggested by you for AMEMBERS() does not work for me (V6s5).

What do you mean "Does not work"? I cannot even test this in version 6 because I no longer have it on any of my machines. The code I posted works just fine in version 8. But the line of code that you have in your code sample below does not match what I posted. If the syntax of the AMEMBERS() function has been enhanced since version 6, you will have to consult the on-line help to see what the usage is in the old version.

Secondly I have a lot of error messages when a lot of properties that cannot be touched are touched (like readonly properties).

This syntax:

lnProps = AMEMBERS( laProps, loObj, 0, 'C' )

In VFP 8, results in a an array of changed properties only (and therefore, cannot contain any properties that are ReadOnly)

As I said before, you need to consult the on-line help for this function in version 6. You may need to use the PEMSTATUS() function to determine if the property in your array is Changed:

IF PEMSTATUS( loOBj, laProps[ lnCnt ], 0 )
  *** Property has been changed

Thirdly, the custom class idea is defeated (this simple header class just had fontbold = .T.) as the properties are restored later the fontbold = .T. changes back to .F.

I do not know what you mean by this.