I've never had an issue with Firefox. Beyond that, sales tax is a slippery slope and many online retailers will charge state tax as long as they have a retail source IN that state. Ever since newegg built a warehouse in TN, I now get charged sales tax, even if the product ships from another location. And Waves also charges sales tax on every purchase(can't remember if I get charges tax when buying Waves from AD or dontcrack.com)
