Hi JCarpenter,
I met exactly same issue as you did.

I tried to subclass QTextEdit:: paintEvent() and do the border painting work myself,
but I found QTextEdit:: paintEvent is actually the Paint handler for QTextEdit::viewport() who has installed an eventfilter, NOT for painting QTextEdit itselft.

On my way of testing I found a solution
Qt Code: 
  1. bool AttachmentListEdit::event(QEvent* e)
  2. {
  3. #ifdef Q_OS_WIN
  4. 	switch (e->type())
  5. 	{
  6. 	case QEvent::Paint:
  7. 		// skip QFrame::paintEvent() to prevent buggy border painting
  8. 		e->accept();
  9. 		return true;
  10. 	default:
  11. 		break;
  12. 	}
  13. #endif
  14.  
  15. 	return QTextEdit::event(e);
  16. }
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Though it works for me, I can not explain it exactly.
I've no idea who finally paint the border but I'm going to dig out.
I'm using Qt4.7.4