Actually David you did not say navigation was slow. This problem could also be due to your ISP or just heavy traffic at the wrong time of the day, there is no point in saying about Steve's suggestion 'not buying it' as you are not dealing with an eBay support guy here. You are replying to some big time users on here.
If everyone found Auctiva ran at dial up speed Auctiva wuold have gone out of business some while ago.
What speed of PC/MAC, OS type, ISP, and browser are you using, feed us some specifics and there may be someone here who can help you.
It works fast here in England even with my 500MHz P3 PC running XP, IE6, 1Mhz broadband on a major (read 'complacent') ISP, so if you have a higher spec set up then there shuold be no problems.
So basically, if there is performance issue it rather limits the performance problem to either your ISP or PC (or even a slow hub on your own LAN).