No me había fijado en los logs (o sudo dmesg) de inicio pero veo que aparece este error:

jnl: unknown-dev: flushing fs disk buffer returned 0x5

no me ha causado problemas, pero que significa este error ?

Saludos.

-Especulación por el mensaje-Parece como si quisiera iniciar un dispositivo desconocido pero por ser desconocido,no lo hace,lo pasa por alto y el sistema desiste el intento. (no me repliquen el mensaje por especular)

Tendrá que ver con algun HDD, encontré algunos post haciendo mención a una partición en lugar de dispositivo desconocido ? aunque en esa pc además de os x tengo windows xp y kubuntu lo raro es que por ejemplo en kubuntu en el log no hay errores ... pero tengo la duda será la misma partición de linux (Ext3) la que este generando el error en Leopard ?

Si puede ser eso el error,pero imagíno que como no usas la partición ext3,no da problemas.Si fuera una partición HFS+ por ejemplo,la situación cambiaría.

Aquí esta el log completo para ver si le pueden dar una checada:

Extension "com.apple.driver.AppleACPIPlatform" has immediate dependencies on both
com.apple.kernel and com.apple.kpi components; use only one style.
Extension "com.apple.driver.ApplePCIConfigurator" has immediate dependencies on both
com.apple.kernel and com.apple.kpi components; use only one style.
mbinit: done
Security auditing service present
BSM auditing present
Extension "com.apple.driver.AppleACPIPlatform" has immediate dependencies on both
com.apple.kernel and com.apple.kpi components; use only one style.
From path: "uuid",
Waiting for boot volume with UUID 66322B4C-984E-3328-88A0-EFD610C3E453
Waiting on <dict ID="0"><key>IOProviderClass</key><string ID="1">IOResources</string><key>IOResourceMatch</key><string ID="2">boot-uuid-media</string></dict>
Got boot device = IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IDE1@1F,2/
AppleIntelPIIXATARoot/SECD@1/AppleIntelPIIXPATA/ATADeviceNub@0/
AppleATADiskDriver/IOATABlockStorageDevice/IOBlockStorageDriver/Maxtor 6Y080L0
Maxtor 6Y080L0/IOFDiskPartitionScheme/Untitled 2@2
BSD root: disk1s2, major 14, minor 4
FireWire (OHCI) TI ID 8009 PCI now active, GUID 106250000000050c; max speed s400.
Jettisoning kernel linker.
Resetting IOCatalogue.
display: family specific matching fails
Matching service count = 1
Matching service count = 2
Matching service count = 2
Matching service count = 2
Matching service count = 2
Matching service count = 2
ACPI_SMC_CtrlLoop::initCPUCtrlLoop - pmCPUControl (PMIOCSETPSTATETABLE) returned 0xffffffff
jnl: unknown-dev: flushing fs disk buffer returned 0x5
USBF: 5.429 DWXBoxHIDDriver[0x3f9ec00]::start - USB HID Device @ 3 (0xfd510000)
Apple16X50ACPI1: Identified Serial Port on ACPI Device=UAR1
Apple16X50UARTSync1: Detected 16550AF/C/CF FIFO=16 MaxBaud=115200
NVDANV50HAL loaded and registered.
display: family specific matching fails
ALCinject: Starting.
ALCinject: Setting layout-id=<data not shown>
ALCinject: Setting PinConfigurations=<data not shown>
display: family specific matching fails
dsmos: Initializing...
dsmos: Hook and decryption contexts set!
Welcome to ControllerMate v4.3.5
dsmos: Starting...
jnl: unknown-dev: flushing fs disk buffer returned 0x5
ERROR: FireWire unable to determine security-mode; defaulting to full-secure.
jnl: unknown-dev: flushing fs disk buffer returned 0x5
AppleRTL8169Ethernet: Ethernet address 00:1a:2b:3c:4d:5e
com_ZyDAS_driver_ZD1211USB: Ethernet address 00:11:22:33:44:55
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
AppleRTL8169Ethernet: phyWaitForAutoNegotiation TIMEOUT <---- No conecto la pc con cable de red
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
krb5kdc 93 FS_READ_DATA SBF /usr/share/icu/icudt36l.dat 13 (seatbelt)
krb5kdc 93 FS_READ_DATA SBF /usr/share/icu/icudt36l.dat 13 (seatbelt)
krb5kdc 93 FS_READ_DATA SBF /usr/share/icu/icudt36l.dat 13 (seatbelt)
krb5kdc 93 FS_READ_DATA SBF /usr/share/icu/icudt36l.dat 13 (seatbelt)
krb5kdc 93 FS_READ_DATA SBF /usr/share/icu/icudt36l.dat 13 (seatbelt)
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5
jnl: unknown-dev: flushing fs disk buffer returned 0x5