At least for me snapshots are not causing lockups. I'm just not able to mount the newly created snapshot. I've never had THAT problem. They always mount correctly.
On the one fileserver I've updated to a 2.6 kernel, I do a snapshot every night of 3 different lvm volumes.. Looking at the last 30 days logs I had
volume 1 - 1 failure volume 2 - 19 failures volume 3 - 26 failures that's A LOT. 26 failures of 30 attempts is almost 100%... Could it be related to the filesystem..? I'm using xfs, and have never been unable to mount a snaphot.
Recently they have been saying new patches have been posted to LKML, so try the latest and greatest vanilla/redhat kernel. I don't know if any of those recent fixes have made it into the SuSE 10.1 kernel or not. I hope not, because then I can hope that 10.2 will be better. I noticed some YOU lvm updates the other week. I've installed them, and hope to see that they help...
Regards, mj