Ok, thanks. I have both, but I was testing it on DBPro.
Now it works. I didn't put it in the plug-ins user folder, my fault.
The testing idea would be to round the decimals for big numbers, so the mantisa keeps below 9 digits, and ensure this way a minimun number of decimals, although it is tedious to analyze which functions take 'limit values', so I'm giving it up.
I did this workaround with my problem: First operate all big integer numbers, praying for a little integer result, then add the decimal places to that little integer.
If I don't do so, I loose all the decimals (if you add decimals to a big integer, you loose them).
I'm sure there are other places in my program that are affected too,
but as long as the user can't 'see' the error, I'll have to live with this.
Still waiting for an official response. (No hurry, good things take time.)