As DavidL reported, my partition was zeroed out, and gparted also crashed.
Once I ran mkfs.ext3 on it, gparted ran correctly.
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gparted crash at start: glibmm-ERROR **
https://bugs.launchpad.net/bugs/617885
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I am also amd64 and the Maverick Release Candidate. My partitions are
fine, but it gets to scanning /dev/sda when it crashes.
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gparted crashes = libparted : 2.3 = glibmm-ERROR **: unhandled exception
(type std::exception) in signal handler: what: basic_string::_S_create