not really sleeping

My laptop sometimes doesn't suspend/sleep when I close the lid. (I can tell because the fan still runs a bit, for example.) Sometimes it does but won't wake. Sometimes it sort of does, sort of doesn't. Sort of doesn't in the sense that the battery is just way weaker than it should be when I wake it. The kern.log shows things like this:

Jan 17 22:37:17 starshine kernel: [32612.982283] pci_bus 0000:04: Allocating resources
Jan 17 22:37:17 starshine kernel: [32612.982312] pci_bus 0000:06: Allocating resources
Jan 17 22:37:17 starshine kernel: [32612.982376] pci_bus 0000:07: Allocating resources
Jan 17 22:37:17 starshine kernel: [32612.982416] pci_bus 0000:08: Allocating resources
Jan 18 20:00:23 starshine kernel: [32623.080391] PM: Syncing filesystems ... done.
Jan 18 20:00:23 starshine kernel: [32623.344971] PM: Preparing system for sleep (mem)
Jan 18 20:00:23 starshine kernel: [32623.345230] Freezing user space processes ... (elapsed 0.002 seconds) done.
Jan 18 20:00:23 starshine kernel: [32623.347439] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
Jan 18 20:00:23 starshine kernel: [32623.348916] PM: Suspending system (mem)
Jan 18 20:00:23 starshine kernel: [32623.348957] Suspending console(s) (use no_console_suspend to debug)

Any suggestions what to look at to make this a bit more sane?

(I know I may have just presented three different problems, or not, but I suspect the strategy for looking for solutions will be similar.)

Thanks.