everything was working fine untill now and suddenly

when i exit my application it vanishes from the screen as usual but when i open my taskbar my app is still running .it never happened.

abt my app

first there is a login screen,when user authen... mdi form loads with a toolbar. i have the function to handle toolbar events in a module .which takes the button.text as argument.

for the exit button i do the following:

unload all child forms
close all open db connections

unload the mdimain(mdi form)
end

.i have been using this sequence of stmts right from the start of my proj.but from yesterday onwards this problem surfaced::the app exits giving an error "that memory referenced could not be written....",if i use the end stmt and
it stays in the taskbar,if i remove the end stmt.

but if the user logs out (i.e go to the first form)and clicks exit ,it exits normally(the first form is a simple non mdichild form ).

what is happening here ??