Traci,
This is a common practice in most older homes. It is an inexpensive solution for a small structural problem. If the support jack looks new, then I would have very serious concerns. You stated it was THEIR inspection report- If everything else is satisfactory about the house, I would seriously consider hiring my own structural engineer to verify that there is no major problem with the structure as some of the house inspectors are dubious in their ability. It is your money and it would definitely help you sleep better at night.