Printing one character over the other when 240x144 dpi with LX-300+II using QTextDocument to print html file on Windows

I use QTextDocument to print an html file on Windows 7. The printer is a dot matrix printer from Epson named LX-300+II. I print from tractor, that is paper is in continuous form. I created a new page format from windows settings to match the form, it is 8 inch wide(width) and 5 inch long(height).When setting the printer to print in 120x144 dpi, there is no problem. But when I set 240x144 from printer settings, vertical placement of characters is fine but horizontal placement is condensed so much that one character is on the other. Printing to ink jet printer, to a pdf printer and xps printer is fine. I also print fine from ms office and notepad. I debug the dpi from printer and it reports 144 whether the setting is 120x144 or 240x144. There are three settings for this printer which are 120x72, 120x144 and 240x144. There are pictures of prints in the attachments.