QPainter::drawText draws distorted text after setStretch

Here is the description of this issue provided by the customer:

We created a QPainter on a QImage to draw various reports on QImage. After we paint the image, we set this image to PDF, Network Printer, Thermal Printer. This image painting engine is common for all the destinations. And we are using QFont.Stretch(); to fit the text appropriate to the destinations.
After font stretching we are setting the font to painter by calling QPainter::SetFont().
At some point of this stretching, we are facing corrupt font for future reports.
We tried using setPointSize insted of stretch but result is same. We are clearing the font using QPainter.end and resetting it back using QPainter.begin. But somehow fonts are still corrupted for this painter. We are using same font on UI also, but that is intact and working fine.

It happens on a mips system with qt/embedded 452