iPC 10.5.6 & Front Row Plugins Issue

I'm having a problem with 'Front Row' on my install of iPC 10.5.6 PPF5 DVD.

The iPC Build installs fine, without issue. I use the 'Azilla Audio' Kext and
an NVinject kext from another post on this forum. All working fine.

After installing a plugin, Front Row seems to load in memory but the main interface does not, nor does it crash with any errors.

I've tried repairing all permissions on the disk, rebooting. Still Same.

I thought it might have been one of the Apple app updates, so I re formatted
and tried immediatly after a fresh iPC install. Issue Reoccurs.

Tried installing all app updates Front Row, iTunes, Java etc.
(excluding 10.5.7 for the time being - causes kernel panic on reboot)
Still Same.

Tried leaving for a several minutes. Still no response.
But if I delete the plugin from the Front Row package directoy, the interface loads just seconds after its been deleted.

I know some would say its a faulty plugin. But I've tried two very different plugins and the issue is the same for both.

NOTE: I also have an Intel Mac Mini running 10.5.6 with all same updates,
and Front Row loads these plugins without any problems.

I'm beginning to think maybe its a framework issue, but wont be able to
compare my systems for another week until I get my mac mini back.

If anyone can offer any thoughts / advice I'd be very grateful.

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Shutdown Plugin:-
dinky tunes.com/downloadpage/downloadpage.html

DVDpedia Plugin:-
br uji.com/extras/dvdpediafrontrow.html

System:-
HP/Compaq DC7600 SFF
P4 3.0Ghz
2Gb RAM
PNY GeForce 8400GD 256Mb
Realtek 8139 PCI NIC