A regularly used piece of code to export a table from SAS to an excel sheet (in a spreadsheet that already exists) has suddenly stopped working.  The code below was used to create a new tab 'sas_update' in the spreadsheet 'policy rule tracking.xls' and previously worked fine.
Now, when the code below runs the first time the various error messages are displayed. 
If it is run a second time (with nothing changed) it appears to work (again message displayed below).
However after either the 1st or 2nd attempts the excel file can't be opened - a message is displayed 'cannot access policy rule tracking.xls'.
I have then found that if I close the SAS session I can open the excel file but the new sheet does not appear!
Any ideas / suggestions would be greatly appreciated.  This has me completely stumped.
Initial Run
  1    libname jgsas 'c:\temp\jgsastemp'; 
NOTE: Libref JGSAS was successfully assigned as follows: 
      Engine:        V9 
      Physical Name: c:\temp\jgsastemp 
2    proc export data=jgsas.policy_rule_tracking_4 
3    outfile='c:\temp\jgsastemp\acquisition tracking\policy rule tracking.xls' 
4    dbms=excel2000 replace; 
5    sheet=sas_update; 
6    run; 
ERROR:  Read Access Violation In Task [ SQL ) 
Exception occurred at (5570C819) 
Task Traceback 
Address   Frame     (DBGHELP API Version 4.0 rev 5) 
5570C819  06F4E1F4  sasjet:mcn_main+0xB819 
55750030  06F4E2EC  sasiojet:mcn_main+0xF030 
6597F5AC  06F4E334  sasxdbi:mcn_main+0xE5AC 
671A331A  06F4E484  sasyoio:mcn_main+0x231A 
06F626CC  06F4E4F0  sassqx:mcn_main+0x116CC 
06F620FD  06F4E5EC  sassqx:mcn_main+0x110FD 
06F618BB  06F4E628  sassqx:mcn_main+0x108BB 
06F771C1  06F4E654  sassqx:mcn_main+0x261C1 
06F739E2  06F4FF54  sassqx:mcn_main+0x229E2 
600D118A  06F4FF88  sassql:mcn_main+0x18A 
01262B02  06F4FFA0  sashost:Main+0xBE72 
01266C20  06F4FFB4  sashost:Main+0xFF90 
7C80B683  06F4FFEC  kernel32:GetModuleFileNameA+0x1B4 
WARNING: The data set _IMEX_.sas_update may be incomplete.  When this step was stopped there 
         were 0 observations and 26 variables. 
ERROR:  Read Access Violation In Task [ SQL ) 
Exception occurred at (5570C819) 
ERROR: Unable to clear or re-assign the library _IMEX_ because it is still in use. 
ERROR: Error in the LIBNAME statement. 
ERROR: Export unsuccessful.  See SAS Log for details. 
NOTE: The SAS System stopped processing this step because of errors. 
NOTE: PROCEDURE EXPORT used (Total process time): 
      real time           0.59 seconds 
      cpu time            0.15 seconds 
2nd run from here
7    proc export data=jgsas.policy_rule_tracking_4 
8    outfile='c:\temp\jgsastemp\acquisition tracking\policy rule tracking.xls' 
9    dbms=excel2000 replace; 
10   sheet=sas_update; 
11   run; 
NOTE: "sas_update" was successfully created. 
NOTE: PROCEDURE EXPORT used (Total process time): 
      real time           0.50 seconds 
      cpu time            0.04 seconds
Message was edited by: J Guthrie