able to hide buttons - not able to show them again

hi,
i am able to hide buttons when i don't want them to appear like this,

CEikButtonGroupContainer* icba=CEikButtonGroupContainer::Current();
icba->MakeVisible(EFalse);
DrawNow();

but i am not able to show them again by using this
icba->MakeVisible(ETrue);

i read somewhere that to make it visible we have to make HandlekeyEvents in AppUi or view i did it but still was not able to make it visible.

i also tried processcommandl, may be i am doing some mistake.

thanks,
sunny