Apostrophes Displaying As Commas?

So I’m having this weird glitch I’ve never seen before on any site…Essentially, all of the apostrophes are displaying as commas on some machines. I have a mac running lion and PC with windows 7 and each machine displays them correctly. I’ve tested several others and they are all fine, however, my supervisors Mac/Snow Leopard is doing this in both Firefox and Safari.

I went to her house to try a few things. I tried stripping all the text css and it still did it. I also ran Firefox with no add-ons in safe mode and same problem. I thought maybe this was a rich text artifact from the e-mail content I was pasting into the site but I made a new page with straight html using just <p>apostrophe’s</p> and same problem…

I’ve never encountered this any suggestions anyone please help? Is there an issue with utf designation? I can’t make heads or tails of it and a google search didn’t yield anything either…Here is the offending site: http://www.postpaintdesign.com If you click on the …read more link at the top the first page has an apostrophe in its first sentence.