My Sporter clean install runs SLOOOOW!

www.mmabigshow.com

It runs really slow. Any idea as to why or how to optimize it?

I should add that it also loads messed up sometimes and I have no idea why.
Some of the admin sections also load with text overlapping eachother etc.

Notice: unserialize() [function.unserialize]: Unexpected end of serialized data in /usr/home/jappleton/domains/mmabigshow.com/public_html/libraries/joomla/cache/controller.php on line 183

Notice: unserialize() [function.unserialize]: Error at offset 1360308 of 1360309 bytes in /usr/home/jappleton/domains/mmabigshow.com/public_html/libraries/joomla/cache/controller.php on line 183


I'm getting those intermitten errors on my homepage as well.

Is there support on this site at all or what?

For the error can you disable system cache plugin and try again to see if this error occurs...