It's commonplace for websites that have a purchasing facility to use two particular types of technology: cookies and Javascript. Cookies are used to pass various pieces of information between parts of a site and Javascript is used to provide 'enhanced' facilities (such as image zooming).
If either are prevented from running, then various problems can arise.

If using Internet Explorer, try resetting your security settings or setting it to 'medium' level.  Many people install add-ons to their browser, such as Google toolbar and others. MyWay Searchbar/Funwebproducts is one such add-on that not only influences your browsing but also is reputed to distribute malware - highly not recommended to use! Consider disabling/uninstalling/removing 'features' that are unneccessary.

[Some browser settings prevent the transfer of information between websites, for example from dragonreborn to PayPal. It is required to allow the flow of information to proceed. Users have many different setups that may prevent this, so it is not possible to predict where issues may arise, with respect to these methods.]

Try a different browser, such as Firefox (recommended), Opera, Google Chrome or Safari. Note that this site has been designed around Firefox and IE7, so you may experience layout issues by using other browsers.

If you still have issues, then please get in touch via the contact form on this site.