Closing Event is called while minimizing!!!

hi,
my application(vb.net-ppc-testing in hp ipaq device) has the minimize button
in the main form. i have done a testing such that i have minimized my
application, again tapped on the exe(maximize it) and done this continuously
for more than 10 times. sometimes even 20-25 times. while doing this, i have
noticed some strange observations:

1) form.closing() event is called. (for a form with minimize button set to
true!!) and it is calling a msg box put inside the event.
2) i have written code in the closing event of some other forms(not main
form). that code is being called when the above operation is performed.
(these forms are already hided by me !!)
3) ONE OF THE GREATEST BUG of my application is- while performing the
operations mentioned above, the content of one particular data file (text
file) get deleted. !!!

kindly respond & give me some tips to sort out these issues,
regards,
hari