I had a similar problem to this but as a work around I drew the image on the ForeLayer of the form, then caught the colour of the Forelayer that was not occupied by the image. Each time the MouseDown event was triggered I use the FGetPixel command to test the colour at that point and if it is different to the colour of the ForeLayer then I know that the image has been clicked
Hope this little work around helps.
Regards,
RandomCoder