NFSv4: cannot allocate memory errors when moving files

Question

When I move a directory on an NFS client to another location then I can't create a file on that other location anymore:
[willem@venus ~]$ mkdir test
[willem@venus ~]$ mv test /pub/music
[willem@venus ~]$ cd /pub/music/test
[willem@venus test]$ touch a
^C
the touch command does nothing on the nfs client (it hangs, so I Ctrl-C).
When I logon to the NFS server the following happens:
[willem@titan W]$ cd /pub/music/test
[willem@titan test]$ touch x
touch: cannot touch 'x': Cannot allocate memory
[willem@titan test]$
This only happens if the mv command moves the directory over different NFS mount points.
I have an older arch NFS server with a 3 months old arch install, and this issue does not occur there.
If I mount the nfs client directories with nfsvers=3 in my fstab then it also does not occur, so it seems to be broken in a recent update in NFS4

Answer 1

I've tested using a very small SGA and PGA (200Mb and 100Mb), although normally I would have it set higher.
# Kernel sysctl configuration file for Red Hat Linux
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.
# Controls IP packet forwarding
net.ipv4.ip_forward = 0
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
kernel.panic = 300
kernel.sysrq = 1
net.ipv4.tcp_syncookies = 1
# Oracle XE Recommended Values
kernel.sem = 250 32000 100 128
kernel.shmmax = 536870912
########