Alvin, Although I don't have a direct answer to your question, I had a similar frustrating experience with LabVIEW and Excel earlier this year. I was seeing strange Excel/ActiveX behavior that took almost a week to isolate and fix. In my case (using Excel 2000) I was making updates from LabVIEW via ActiveX and had different behavior in LabVIEW vs. a LabVIEW Application (built executable). In the built executable Excel would lock up, but in the LabVIEW environment it worked fine.
After fighting with it for several days I found the cause to be the way I was handling a worksheet refnum. In one section of my code I had a refnum going to a case structure where 2 different operations occurred; in one case I used the "Activesheet" property whereas the other I used a user defined sheetname. To make a long story short, the case structure worked fine in LabVIEW, but not when built as an application. I ended up doing both operations in series and ignoring the information I wasn't looking for. One way I could detect the problem was when I looked in the task manager I would see Excel open when it should have been closed. So as a long shot suggestion, I guess I'm saying that I've also see behaviors in LV/Excel that seem to cause latent issues that are very hard to isolate. Perhaps you are seeing the same issues I saw since you are opening and closing worksheets. If that's no help, at least take some solace in knowing someone else "feels your pain". Let me know if you want more information about what I saw and how I fixed it. John ____________________________________________________________ John W. Morrissey [EMAIL PROTECTED] Principal Test Engineer Sycamore Networks 220 Mill Road Chelmsford, MA 01824 (USA) Tel (978) 367-8041 Fax (978) 250-9405 Pager [EMAIL PROTECTED] ____________________________________________________________