logs filling up with eCryptfs error messages

I am observing a constant stream of the following error message filling up my /var/log/messages:

`Either the lower file is not in a valid eCryptfs format, or the key could not be retrieved. Plaintext passthrough mode is not enabled; returning -EIO`

I have already tried to find a solution to this. I am not sure if this actually a bug or a configuration error.
I did find a bug report under https://bugs.launchpad.net/ubuntu/+source/ecryptfs-utils/+bug/372014 , which does not really point to a solution.

I already tried to `rm -R ~/.cache`, which did not resolve the problem.

Not sure if this could be related or a totally different problem:
I am also having trouble changing permissions on some files in `/home/myuser/` when issuing `sudo chown myuser:myuser ~myuser -R` resulting with an io-error on some files.
I have already checked the sanity of the unmounted, encrypted filesystem via `e2fsck -c` and the state of the disk itself with smartmontools, which both indicate that the disk and filesystem are ok.

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My system info:
separate /home partition encrypted with eCryptfs and formatted with ext4

lsb_release -a
LSB Version: core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick
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uname -r
2.6.35-28-generic