It may not be related, but instead of Calculate, I would use a SQL Select statement instead, since it doesn't move the record pointer.

IF !EOF('inspdata') AND !BOF('inspdata')
   local lnjobnum
   lnJobnum=inspheader.jobnum
   Select max(itemnum) from inspdata where jobnum==lnJobnum into array lnMaxItem
   RETURN lnMaxItem
ELSE
   Return 0
endif

>I seem to be having a new issue with one of my applications.
>
>An error is being returned, Update Conflict zgetmaxitem line 4 data source inspdata.
>
>inspdata is a table in a database that is part of a form's DE. Shared, not exclusive.
>
>The zgetmaxitem is a procedure I have defined in the form.
>
>as follows;
>
>

>IF !EOF('inspdata') AND !BOF('inspdata')
>	LOCAL lnRecNo
>	lnRecNo=RECNO('inspdata')
>	CALCULATE MAX(inspdata.itemnum) FOR inspdata.jobnum=(inspheader.jobnum) TO lnMaxItem && == is not necessary with numbser!
>	IF lnRecNo>0
>		GO lnRecNo IN 'inspdata'
>	endif	
>	RETURN lnMaxItem
>ELSE
>	RETURN 0
>endif
>