Strange errors on LVM2 snapshot create.

I'm running x86 Linux 2.6.9, with the 2.6.9-udm patches, lvm2-2.00.02, device-mapper-1.00.17.

Occasionally, when I try creating a snapshot, I get the following out of lvcreate:

device-mapper ioctl cmd 9 failed: Cannot allocate memory
Couldn't load device 'shadowdb-homesnap'.
Problem reactivating origin home
device-mapper ioctl cmd 6 failed: Invalid argument
Couldn't resume device 'shadowdb-homesnap'
Aborting. Failed to activate snapshot exception store. Remove new LV and retry.

There is also an accompanied kernel message that I'll send once I can get this to happen again while I'm at the machine.

Is this problem known? Should I try building a newer version of the lvm2 utilities, and device-mapper library?

Any pointers?

Thanks,
Dave Brown