Hello Guys!,
I don't know if this is old news, but I found a way to update class libraries and reports without interrupting the users, I tried it and it works!, this is what I do, lets say that I made some changes to a class library, then I want to update the version being in use that resides in the network, I open the old and
new VCXs files as tables and update record by record from the new to the old one. here is a short vertion of the code :

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Method Name : UpdTable *
* Description : Update a class, report or any table with data from *
* another table of the same structure,
* it compares the two table record *
* by record, and update from the source *
* Parameters : tcFromTableName : Character, name of the source table
* tcToTableName : Character, name of the table to be
* Return : Numeric : 0 means sucesfull
* Author : Luis Guzman 01/07/2002
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

LPARAMETER tcFromTableName,;
tcToTableName

* When I say table read "VCX" or "FRX" file of a class library
* or report

LOCAL lcOldSetDeleted,;
lnRowCounter,;
lcCommand,;
lnlnTotalRecords,;
lnCurrentRecord

lcOldSetDeleted=SET("DELETED")
tcFromTableName=ALLTRIM(UPPER(tcFromTableName))

SET DELETED OFF
SELECT EVAL("tcFromTableName")

lnTotalRecords=RECCOUNT(tcToTableName)

DO WHILE NOT EOF()

llIsDeleted=DELETED() && Check if the record is deleted
lnCurrentRecord=RECNO() && Save the current record number

SCATTER MEMVAR MEMO && Load into memory all the
&& information for that record

IF lnCurrentRecord>lnTotalRecords && a new record, insert
&& a row

INSERT INTO &tcToTableName FROM MEMVAR
SELECT (tcFromTableName)
SKIP
LOOP
ENDIF

SELECT (tcToTableName)
GO RECORD lnCurrentRecord && Go to the matching record
&& number
GATHER MEMVAR MEMO

IF llIsDeleted && If the record is deleted in the
&& source, delete tha record from
DELETE && the second table
ELSE
RECALL
ENDIF

SELECT (tcFromTableName)
SKIP

ENDDO

SELECT (tcToTableName)
IF !EOF()
SKIP
ENDIF

DO WHILE !EOF() && Eliminate reminning records
DELETE
SELECT (tcToTableName)
SKIP
ENDDO

SET DELETE &lcOldSetDeleted

* Now you can compile the class library or report and your are ready to go

What do you think?, any comments?