Firefox oddness!! Change to serif on link click

[bydesign]

Here's my website: http://www.flinthill.org.uk/
Click on the navigation links and the font changes from the styled font to an unprescribed serif. Dunno if this is a css issue at all - but it's very odd behaviour that is not happening in other browsers.

Here's the font stack - not a serif in sight.
font-family: “Helvetica Neue”, Arial, Helvetica, sans-serif;

There are no serifs in the style sheets, so I really am at a loss here.

Anyone come across this issue?

I am using html includes for the content area in my php pages to support cushycms - very simple wysiwyg editing software for my client.

[Frank62]

Everything is OK here in FF4, as you can see for yourself (I clicked myself to 'the boys'): http://prntscr.com/2pyvm.

I sometimes have problems with getting php pages refreshed in my preview after changes, if I view them locally. On the server it is never a problem. Have you tried it on the server already?

[bydesign]

Thanks for checking Frank62. I've not noticed a problem on FF - but have very recently updated to FF6 - I wonder if this is anything to do with it.

The site is on the server - so wysiwyg… not sure what you mean otherwise (or maybe I'm being dim here).

[Frank62]

I've not noticed a problem on FF

But the title of your post reads: 'Firefox oddness!'?

The site is on the server - so wysiwyg… not sure what you mean otherwise (or maybe I'm being dim here).

Please forget that remark I made - I was solving two problems at the same time and mixed things up.

[bydesign]

Oops… I am making this much more confusing. What I'd meant to say, is that prior to going on my hols three weeks ago (when I'd uploaded the website), I'd not noticed any issues with FF - but on checking recently the issue arose. I wonder if anyone else has had any issues with FF6.