freepascal - TMemo issue on Windows Mobile 6.1 -

i'm writing simple terminal application windows mobile. opens serial port, , dumps whatever data coming tmemo. application works fine on windows mobile 5, on windows mobile 6.1, memo acts strangely. after 100 characters, no more text added memo , not paint (e.g. if open start menu , close it, text not shown anymore). used code in simple application , reproduced issue. thoughts?

procedure tform1.button1cick(sender: tobject); begin   while not application.terminated   begin     mmport.text := mmport.text + chr(random(90) + 32);     if random > 0.9       application.processmessages;   end; end;