The problem does not appear to be limited to Mozilla software however, as more general shutdown problems are currently being discussed on Apple's support forums. In most or all cases it appears that users are left staring at the "loop," the same loading symbol that appears when first loading Mac OS X. A number of homemspun fixes have been suggested, including the removal of things like Qmaster services, or anti-virus login items. Less dramatic options may include fixing permissions on the boot drive, or removing USB and FireWire devices one-by-one.