harmmeijer,
That is an interesting kanundrum. One thing you may need to do is to create a new form, copy the controls (select all the controls you want when viewing the form, Copy, Past into new form) and copy the code. (copy code from one form to the other). Then remove the old form, rename the new form to the original form name and everything should sync back up. When you copy the controls, all the options will be copied (including names) so it should paste in the new form with no problems.
Andy's solution will work but the image will still show up when you are editing the form. If you want to get rid of the picture entirely, I'm afraid you'll need to create new form and copy. VB encodes the information for the picture in the .frx file and it doesn't appear editable. (I can't make sense of it, but if you can, more power to you!)
Hope that helps.
-crater