In a Microsoft Visual Basic for Applications macro (Excel
2000), when I attempt to put a formula in a cell
in some cases I receive the following run-time error:

Run-time error '1004':
Application-defined or object-defined error

For example, the first 3 statements bellow works fine,
but the 4TH doesn't:
..
..
..
Worksheets("Radni nalog").Range("F3").Formula
= "='Planska kalkulacija'!F3:G3"
Worksheets("Radni nalog").Range("H6:Q6").Formula
= "='Planska kalkulacija'!H6:Q6"
Worksheets("Radni nalog").Range("AF6").Formula
= "='Planska kalkulacija'!Y6"
'The next statement doesn't works:
Worksheets("Radni nalog").Range("AC19").Formula = _
"=PRODUCT('Ostvareni indirektni troskovi'!
T12;'Radni nalog'!AC13)/ _
OFFSET('Ostvareni direktni troskovi'!
P10;+'Osnovni podaci'!R8;0;1;1)"
..
..
..
If I remove the equal sign from the beginning of the
formula,
the formula will be placed to the cell!(Of course, it has
no sense without =)

Could anyone help me?