Does anybody have any recommendations for helpdesk software?

We're currently using an older version of Intuit Track-It! Standard but it's rather slow. The sales guy say the latest version is alledgely faster because it actually uses a proper DB instead of just a massive Access MDB file. Considering it takes around 1 minute just to start up the client app and 10 seconds to open each work order it's not going to be hard to be "faster". The client PCs are all P4 2.8GHz minimum so they're not particularly old or slow.