The Thermals have squeezed a lot of mileage out of a simple pop-punk machine. From the blown-out angst of 2003’s More Parts Per Million to the thumping triumph of last year’s Now We Can See, the Portland trio always injects fresh fuel and fury into its buzzing hooks and ebullient charm. But while the post-Bush euphoria of Now We Can See felt urgent, the band’s new full-length, Personal Life, sounds exhausted. The disc’s single, “I Don’t Believe You,” is one of the catchiest songs frontman Hutch Harris has ever written, but it isn’t indicative of Life as a whole; simmering tracks such as “Alone, A Fool” and “A Reflection” build slowly but never deliver, and navel-gazing lyrics like “It’s so hard to be alone after the heat I’ve felt / after the love I’ve known” are introspective to the point of myopia. Sounding like Craig Finn’s bratty kid brother, Harris redeems himself on the bass-driven, uncharacteristically subtle “Never Listen To Me” and “You Changed My Life,” the latter of which is a spurt of aching, bittersweet pop that pushes the album handily across the finish line. To its credit, the disc sounds like a band tweaking its signature noisemaking and groping toward something new. That transition promises to be amazing, but Personal Life feels more like a weary shifting of the gears than a drive to a definite destination.