Welcome to the forum.
Can you tell us which version of PCLinuxOS you are using. Is it the 2009.2 version? If it is, did you know that a brand new 2010 release has just become available for download
You can try opening Synaptic, and press the "Reload" icon, wait for it to refresh and then look for an app named "flash-player-plugin"
Once you've found it, right click on it and select "Mark for Installation" > then press the Apply icon and wait for that to install.
If "flash-player-plugin" is already installed do the same as above but this time select "Mark for Re-Installation"
Go to FFox and retry the site.
BTW, have you got any "script" addons (NoScript for example ?) installed in FFox as that can block access.
I just tried the site and I can gain access to it (once I've told NoScript to "allow" access)