I noticed another thing

If the program that calls the dll contains a

Public Declare Function multiplicar Lib "proyecto1.dll" _
    (x As Double, y As Double) As Double

the error is 453 (cannot find the entry point "multiplicar"

if I comment the Declare statement out, the error becomes

430, this class doesn't admitt Automation or doesn't addmit the expected interface (or something similar, I am translating from Spanish)

Does it help in getting some light in the problem?

thanks

It already works.

It was my fault, the reference in the VB code pointed to an old version of the dll, ... I have referenced it back and works as expected...

anyway, using the Public Declare .... still doesn't find the entry point, but doesn't matter, because without that statement it works anyway....

sorry for any inconvenience caused by this stupid mistake of my own