Strange form behaviour

[EMW]

I am busy with a program for my pocket pc. but since it is still compact
famework, I'll post this here too, because I'm very much in need for some
help with this:

I have one form which is my main form and has 4 option buttons and two
regular buttons, one for saving and the other for canceling the program.

When the user select an option button, a new form is opened and he can fill
in some fields by using a context menu (standard answers).

When he is finished, tapping on the save button, the form is hidden and the
user is returned to the main form, where an image is drawn that the form is
filled in and done.

After that the form is disposed

After the second button he chooses the third option, but the form of option
2 is show, by either tapping on save or cancel, the form is hidden/closed,
and the form that should have been displayed is opened.

When clicking on the save or cancel button, an exception error occurs, a
disposed exception.

The same thing happens when the second option is skipped and he goes first
to the third option and then the fourth.

Instead of showing the fourth, the third is shown and after closing it, a
disposed exception appears.

Basicly this is what is done:

a.. create instance of new form
b.. set the textboxes with text from dataset table
c.. show the form with showdialog
d.. dispose of the form when it returns
Nothing fancy, but with that strange error.

Who can help me with this??

rg,
Eric