>Adrian,
>
>>> thanks for the answer.
>
>Your welcome, however I think George beat me to the answer.
>
>>> You Talk about C++ but my program is devoloped in VFP6, how can it be?.
>VFP6 is written using C/C++ as are most printer drivers.
>
>>> The aplication shows me thath error just some times and enywhere; for
>>> example clicking in a checkbox or printing. It happends on some PC, not in
>>> all.
>
>We had a similiar problem which was eventually traced to a bunch of older HP printer drivers. Solution, latest versions.

This came up recently with a newer driver. See thread#464893