Since it hasn't worked since your paper jam, I would still suspect that as your cause rather than a software problem. There will be one or more paper sensors within your printer and it only takes a tiny piece torn off the corner of a sheet to activate it and make the printer think there is a jam. Also, because you were using thin paper, a sheet may have concertina'd up into a very small strip that is not easily seen.
I would thoroughly check out the innards of your printer and hopefully you will find the offending scrap of paper.