If your image is in the directory c:\sesame\pics
And your data is in c:\sesame\data
I believe your command line should read

C:\Sesame\Program\sesame.exe –splash c:\sesame\pics\image_myimage.bmp c:\sesame\data\StAndrews.db


it should be showing a dash character infront of the word splash not the –

The good news is that the Sesame splash image is supressed.
The bad news is that my image never comes up.
I get no error message, just no image.
Any ideas?

It means that either your image was not found at the path specified or that the image is not in a supported format.

Can you load the same image into an image field?

If so, does the path have any spaces in it? If so, remember to wrap the path in double quotes.

If you can't load the image in an image field, check to make sure that it really is a format supported by Sesame. Sesame tends to be overly legalistic about the image formats. If, for example, the image is a BMP, try converting it to a JPeg. Often a conversion will repair descrepencies in image formats.