git-bisect failed me again

Trying to find a recently-merged box-killer in Len's tree:

bix:/usr/src/git26> cat .git/branches/git-acpi git+ssh://master.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6.git#test

git-checkout git-acpi git-bisect reset git-bisect start git-bisect good ff2fc3e9e3edb918b6c6b288485c6cb267bc865e git-bisect bad 9011bff4bdc0fef1f9a782d7415c306ee61826c9

And it led me to

bix:/usr/src/git26> git-bisect good
9011bff4bdc0fef1f9a782d7415c306ee61826c9 is first bad commit
diff-tree 9011bff4bdc0fef1f9a782d7415c306ee61826c9 (from 7e1f19e50371e1d148226b64c8edc77fec47fa5b)
Author: Len Brown <len.brown@intel.com>
Date:   Thu May 11 00:28:12 2006 -0400

    ACPI: delete newly added debugging macros in processor_perflib.c
    

which isn't a buggy patch.

bix:/usr/src/git26> cat .git/BISECT_LOG git-bisect start # good: [ff2fc3e9e3edb918b6c6b288485c6cb267bc865e] ACPI: EC acpi-ecdt-uid-hack git-bisect good ff2fc3e9e3edb918b6c6b288485c6cb267bc865e # bad: [9011bff4bdc0fef1f9a782d7415c306ee61826c9] ACPI: delete newly added debugging macros in processor_perflib.c git-bisect bad 9011bff4bdc0fef1f9a782d7415c306ee61826c9 # good: [c52851b60cc0aaaf974ff0e49989fb698220447d] P-state software coordination for speedstep-centrino git-bisect good c52851b60cc0aaaf974ff0e49989fb698220447d # good: [7e1f19e50371e1d148226b64c8edc77fec47fa5b] ACPI: UP build fix for bugzilla-5737 git-bisect good 7e1f19e50371e1d148226b64c8edc77fec47fa5b

A had a second go - fed it the very first and last commit IDs in that tree.
 Same result.

bix:/usr/src/git26> git-bisect good
9011bff4bdc0fef1f9a782d7415c306ee61826c9 is first bad commit
diff-tree 9011bff4bdc0fef1f9a782d7415c306ee61826c9 (from 7e1f19e50371e1d148226b64c8edc77fec47fa5b)
Author: Len Brown <len.brown@intel.com>
Date:   Thu May 11 00:28:12 2006 -0400

    ACPI: delete newly added debugging macros in processor_perflib.c
    
    Signed-off-by: Len Brown <len.brown@intel.com>

:040000 040000 f7a3b4cfdb128fb6a777b2e30a83c63edd70f46a 2ca1c42aaae65df9052d60d274aaec3116e30c2d M drivers bix:/usr/src/git26> cat .git/BISECT_LOG git-bisect start # good: [74951d613e758f9709d6f2173107be68f18f77f4] ACPI: Remove debugging macros from drivers/acpi/thermal.c git-bisect good 74951d613e758f9709d6f2173107be68f18f77f4 # bad: [9011bff4bdc0fef1f9a782d7415c306ee61826c9] ACPI: delete newly added debugging macros in processor_perflib.c git-bisect bad 9011bff4bdc0fef1f9a782d7415c306ee61826c9 # good: [c52851b60cc0aaaf974ff0e49989fb698220447d] P-state software coordination for speedstep-centrino git-bisect good c52851b60cc0aaaf974ff0e49989fb698220447d # good: [7e1f19e50371e1d148226b64c8edc77fec47fa5b] ACPI: UP build fix for bugzilla-5737 git-bisect good 7e1f19e50371e1d148226b64c8edc77fec47fa5b

What did I do wrong this time?

Thanks.