windows - mdi child doesn't show maximized -

we're having following issue in our application: when open mdi childform comes in maximize windowstate should shown in normal state.tthe background parent still visible on right , bottom side.

however when change childform normal state , maximize again shown maximized. when application closed , restarted form comes again issue.

can me solve problem?

is problem related windows? or else?

private sub tbrmngr_toolclick(byval sender system.object, byval e infragistics.win.ultrawintoolbars.toolclickeventargs) handles tbrmngrceres.toolclick      try          '--> handle click '         if not e.tool.sharedprops.tag nothing              select case ctype(e.tool.sharedprops.tag, string).toupper                 case "m_management" : handlemanagementclick(e.tool.key)             end select          end if      catch ex exception         messagebox.show(ex.message) 

here case selected button on th menubar has been clicked. problems come within handlemanagementclick

 private sub handlemanagementclick(byval pstrkey string)      try          dim lblnnonmodal boolean = true          if not me.ifrmactiveform nothing             if not ifrmactiveform.disposing                 ifrmactiveform.windowstate = formwindowstate.normal                 ifrmactiveform.dispose()                 ifrmactiveform = nothing                 inotifiers = nothing             end if         end if          me.cursor = cursors.appstarting          select case pstrkey.toupper             case "res" : me.ifrmactiveform = new frmreservationwizard(me.iclsapp, "res")             case "rcat" : me.ifrmactiveform = new frmfacilitycategory(me.iclsapp, "rcat")             case "rgrp" : me.ifrmactiveform = new frmfacilitygroup(me.iclsapp, "rgrp")          end select          if not ifrmactiveform nothing             if pstrkey.toupper.equals("res")                 'ifrmactiveform.showintaskbar = false                 ifrmactiveform.showdialog()                 ' me.showscreen(formwindowstate.normal, false, lblnnonmodal, formstartposition.centerscreen)                 ifrmactiveform.dispose()             else                 me.showscreen(formwindowstate.maximized, false, lblnnonmodal, formstartposition.centerscreen)              end if         end if      catch ex exception         messagebox.show(ex.message) 

as see windowstate property set on maximize @ showscreen sub.

 private function showscreen(byval pwindowstate formwindowstate, _                             byval pblnregisterchild boolean, _                             byval pblnismdichild boolean, _                             byval pstartposition formstartposition) dialogresult      dim ldialresult dialogresult = dialogresult.none     dim lblnopeningscreen boolean      try          if not lblnopeningscreen              lblnopeningscreen = true              me.inotifiers = nothing              if pblnismdichild                  if pblnregisterchild registerchild(addressof ifrmactiveform.parentnotifier)                  ifrmactiveform.windowstate = pwindowstate                 ifrmactiveform.mdiparent = me                 ifrmactiveform.show()              else                 ldialresult = ifrmactiveform.showdialog()             end if          end if          return ldialresult      catch ex exception         messagebox.show(ex.message) 

i hope covers bit more documentation.

kind regards,

kristof