I tried linux-image-2.6.34-999-generic_2.6.34-999.201005061008_i386.deb and the problem no longer appears. I even reverted to stock 2.6.32-22-generic and reproduced the problem easily. A sure way of reproducing the problem is to access the host with unison through its external IP and NIC (even though the client is on the internal network where the host also has an IP and NIC). This may indicate that the bug appears only under full load or after a certain (2GB?) amount has been transferred.
I tried linux-image- 2.6.34- 999-generic_ 2.6.34- 999.20100506100 8_i386. deb and the problem no longer appears. I even reverted to stock 2.6.32-22-generic and reproduced the problem easily. A sure way of reproducing the problem is to access the host with unison through its external IP and NIC (even though the client is on the internal network where the host also has an IP and NIC). This may indicate that the bug appears only under full load or after a certain (2GB?) amount has been transferred.