Felipe Dana/AP/Press Association ImagesMost headbangers of a certain age have gone through thisheading to our local music store in anticipation of snatching up the latest album by our favourite band on the day of its release. We rush home and throw it on our stereo, ready to once-again to be blown away - after all, their other albums were awesomehow could this not be? But as the album plays on, something is amiss. What pumps from your speakers is not what you were expecting. You cant always put your finger on whats wrong, but this is definitely not the music which made you love them in the first place. Maybe your band is stretching its wings and itll take several listens for you to warm up to it, maybe the frequent line-up changes have changed its sound - or maybe your band is committing the ultimate sin of selling-out. Whatever the case, its always a bit jarring when they decide to shake things up by confounding your expectations. This is especially true with hard rock and heavy metal, whose fans are a lot like our grandparentsresistant to change unless its so gradual that they dont notice (like Rushs evolution from a hard rock bar band to a progressive metal giant). Change isnt always a bad thing, but sometimes it comes too quickly for everyone to readily accept. The following isnt a list of the worst albums by bands weve grown to love (though a few are terrible). Some of them are actually very good (and one is a classic), but at the time of their release, they definitely challenged the loyalty of fans who embraced these bands in the first place.