I have used the Brock Script font for titles on my website and I need to make some more similar titles, however the apostrophe has now changed its form when I use it in Photoshop. In "MS Word" it's still ok. The apostrophe, instead of being a short thin straight line now comes out in the form of a comma. Does anyone have an idea as to why this is happening? Thank you.

Could be many reasons, personally I don't tend to put my faith in Microsoft even when it comes to testing fonts.

It could well be the way it was coded ie, Truetype or possibly the way it was made. However I tested it in both Photoshop and Word and it worked fine in Photoshop but not Word. When I used it in word i didn't even get an apostrophe but instead I got an "Otilde" glyph.

Without completely dissecting the font I can't be absolutely certain.

Have you tried posting over on a type forum for some feedback?