Nivo Slider breaks when placing classes or links in the text captions

I’m trying to put some links and classes in the slider text captions but this always breaks the slider. There’s no problem with <br />, <em>, <strong> or heading tags, but when I try classes or links the text styling reverts to the default paragraph text, jams it above the images – forcing them down – and generally displays /> after the text. Can provide links and snapshots of the code I’m using if required.

Thanks for helping . . .