hi high_flyer,
thnks for ur time and reply.
This part suggests to me, that there is a problem with the focus, which then might explain why you don't see the cursor.
yes, some problem in setting the focus when using onscreen tab key.
Interestingly i found that when i directly touch the lineedit(having some text) the vertical beamer is
blinking .
but when i press the tab key, the beamer in linedit(having some text) is visible but its not blinking.
when i type some characters in lineedit using onscreen keyboard, the beamer is visible but its not blinking.

This problem comes only in openembedded. in ubuntu pc the cursor is blinking well for the above scenario.

may be the implementation is wrong(the focuswidget and sendkeyevents)
or some problem with the sending keyevents QKeyEvent keyEvent(QEvent::KeyPress,nKeyId,Qt::NoModifier,qs trKeyIdString);

still not able to find why the beamer is not blinking?

Bala