MIME Type error reading image file in Custom Report Item

I have a Dundas chart for reporting service 2005. I want to use a BMP file as texture(pattern) for a FillPolygon(GDI+) in chart PostPaint event. I'm getting MIME Type error reading image file when Preview report, where I have to put BMP file for report developement and where to set MIME Type?

Thank you very much, SorinB

[337 byte] By [SorinB] at [2007-12-25]