imagelibexdevice SaveImage pb

HI,
For my project, I use imagelibexdevice library.
With Klauss and agraham Help (thanks), program run nice and quick. But a problem is still occur : bmpDummy.SaveImage(FileNameTB.Text,"J") not works and returns me an error "NotsupportedException".
To try the code, i use Klauss program draw (http://www.b4x.com/forum/share-your-creations/3945-draw-program.html).
The same error occurs.

I don't understand what is the problem.
:sign0085:
My device is Asus Mypal 730

What Operating system do you have ?

If it's WM 2003, it supports only saving bitmaps !

Best regards.

Is the error on device or desktop?

If on the device do you have .NET CF 2.0 installed? Bitmap.SaveImage is not available on .NET CF 1.0 but if .NET 2,0 was missing I would have thought the library would not load.

If on the device are sure you are using "J" for the format. On early devices "J", "G" and "P" are not available and will give this error.

It's much easier than guessing if you post a small example of the actual code that does not work

Thank for Help!.
Klauss, you win all my congratulations : The problem occurs because Wm2003 on device.
For desktop, program runs good, but with device (Asus A730 mypal, under Wm2003SE) program fails.
If I change parameter for saveimage, program runs good under WM2003
under WM2003, change bmpDummy.SaveImage(name,"J") by BmpDummy.SaveImage(name,"B"),

Program run, but too slowly for its usage.:sign0161:

I must try to save only parameters, not graphs and redraws them on image.:BangHead:

I go to learn Arrays...:sign0060: