Problem with tImageList

I have an ImageList, which is creating some stange problems.

If I change the Width or the Heigth property of the list my application
issues a memory error in the main Delphi dcu/dll. At least when running
i debug mode.

The same goes, if the images in the list are monochrome, or if
ImageList1.GetBitmap() points to an image with the Strech property set
to true.

After the error the entire Delphi simlly hangs !

I have not tried to run the application in stand-alone.

I have seen some of this before, something to do with an obsolete way
Delphi uses video memory.
I am using D6-prof. Have anybody seen a work-around for this ?