Massimo,
You need to be very careful which order you close your references in.
You need (generally speaking) to close them in the reverse order to opening.
If you open a worksheet, then a reference to a cell you will need to
close the reference to the cell first, then the reference to the
worksheet. Closing the worksheet with an open cell reference on
the worksheet will not work and will ultimately cause the Excel
application to remain open.
Make sure you're doing this and you should be fine. Additionally,
double-chesk that you're really closing ALL references. Some
functions can produce new references which will also need to be closed.
Hope this helps
Shane.
Using LV 6.1 and 8.2.1 on W2k (SP4) and WXP (SP2)