[Samba] Poor performance via FUSE

[HN Plato]

First a little background

Over the last year I've been using samba 3.x with great success. Client 
machines are in a Samba domain, performance is excellent over gigabit.

Recently I've installed FUSE and have been using a fuse module EncFS to 
provide disk-level encryption. Samba over a mounted FUSE volume works. Read 
performance is good, and CPU utilization is modest.

However the problem comes in for writing large amounts of data. Using a 
command line interface, copying 4GB or so of  data takes an hour. Copying 
via the explorer interface hangs the machine after a period of time (the 
progress bar is also inaccurate).

Has anyone attempted this configuration? Any suggestions on how to identify 
where the problem is (or solutions that pop to mind?)

Any assistance is very much appreciated.

-h


Equipment specs

System Configuration
Fedora Core 2
2.6.10-1.9_FC2 Kernel
Samba 3.0.11-1 made with rpmbuild
Software Raid 5 (md)

Hardware configuration
P4 2.4Ghz
1GB Ram
4 200GB SATA drives using promise controller (sata_promise kernel module)
Intel e1000 Gigabit adapter