As a rule of thumb I avoid setting anything on HTML in the first place -- it's too inconsistent in behavior cross browser... I'd get rid of that first. It's not worth the extra code or headaches which is why you do NOT see a lot of websites bothering to do that, and the ones that do usually end up with broken layouts for somebody!
Second, fixed footers generally are more of a headache than they're worth -- and as Paul noted the technique you are using doesn't work anyplace but FF and Chrome (here it doesn't even work in Safari!)
Now, I've never heard of Silverstripe, but researching it and the code from it's site and examples, they are saddling you with a bunch of idiocy that just extends the problem I have with so many off the shelf CMS -- it's like the people who write these softwares aren't qualified to write HTML or CSS.
Case in point, the resulting site of yours -- HTML5 doctype so kiss off having a USEFUL validator (since HTML5 is still in draft it should NOT be used on production pages), IE conditional nonsense, tags like 'base' that shouldn't ever be neccessary or used on a modern websites, Conditional BEFORE the primary CSS forcing the use of inheritance overrides and !important in the IE specific sheet, Three separate stylesheets for no good reason other than using twice as much CSS as necessary, inclusion of jquery for Christ only knows what... and that's BEFORE we even talk about the contents of the body tag with it's endless pointless nested DIV, improper heading orders, and presentational use of classes.
There's a saying of mine -- CSS is only as good as the markup it's applied to -- and this markup is problematic at best, overthought at worst.
None of that is likely your fault -- every one of that CMS' example pages appear to be similarly badly thought out...
Like the two div and img tag doing H1's job, the lack of images off graceful degradation (which would add a SMALL tag, some text and a span), the triple DIV around the UL for nothing, the double div around the content area for nothing, the pointless LINK class on every A inside the menu (if they all get the same class, they don't need a class) etc, etc...
IF I was writing that same layout, the first step would be rewriting the markup thus:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
Testimonials - A Capellago
<small>Songs of Passion and Hope from Around the World</small>
<li><a href="/silverstripe/upcominggigs/">Upcoming Gigs</a></li>
<li><a href="/silverstripe/contact-us/">Contact Us</a></li>
<!-- #sideBar --></div>
If you have a comment about an A Capellago event, we'd love to hear from you.
Dear Nikki and A Capellago,<br />Medicine Music was the most beautiful gesture, thankyou so very much.* It will remain with me as a perfect image of redemption - you all singing like angels in that broken building.* Somehow that speaks in the most touchingly eloquent way of human grace and resilience.* You reminded me of the miracle we are in the middle of - the amazing flowering of Christchurch at this time.* Spring welling up irrepressibly from the very same Earth that has groaned and torn under us.<br />
Thankyou, and bless you<br />
Your are one of Christchurch's real treasures<br />
With love<br />
Jane Catherine Severn
Many thanks to the choir and other supporters for the wonderful concert on saturday afternoon. It was truly magical and I felt I could let go of the grief*I have been feeling since sept 4. Thank you again, yours truly, L. S.
Hi Marissa<br />
I was at the performance of A Capellago World Music Choir in the Cathedral a week or so ago and I wanted to tell you what a mesmerising and touching performance it was.<br />I was completely absorbed, the music was fabulous, the singing stunning, thenarrations in between just perfect.<br />
And I absolutely loved your poem.<br />
Well done to you all. I hope to see you all perform again.<br />
2 questions for you:<br />
1. How do we find out about your performances, and<br />
2. Is your poem published, I'd love to revisit it<br />
Thank you so much for the inspiring afternoon<br />
<!-- #content --></div>
<!-- #pageWrapper --></div>
A Capellago Music Choir - Christchurch, New Zealand - phone 348 1219 - email firstname.lastname@example.org
Which despite using the larger doctype and closing element comments still throws about a quarter of the markup in the trash. If I have time later I'll toss together the CSS I'd use with that... though that bottom right image may end up requiring one extra DIV.
Though that's not EXACTLY how I'd write it since you're using breaks and double breaks on multiple paragraphs, and those testimonials should be in blockquote tags... though I suspect that's probably the fault of the CMS not having a decent editor on the back end.