Cisco Switches :: SGE2010P And SGE2000P LAG Configuration

I've got multiple SGE2000P & SGE2010P switches
 
Originally I was happy just set them all up in a stacked ring configuration. However I've become aware that my back bone fibre links are contantly pushed to their max.
 
So I've decided that I should change this configuration and unstack the switches and make them all stand-alone units. and I'll configure 2 cable LAG links between all my switches Theorically I should now get 2GIGs between each switch and to complete the ring in my network for redundancy I'll turn on Spanning tree.
 
However I've tested the speed and I just can not seem to get a LAG connection with 2 x 1gig cables to push more data than a single link 1gig link cable would.
 
My test enviroment(not using fibre optic cables just cat5e copper cabling):
4 x pc's(all gigabit network cards)
2 x sge2000p switches
PC1 ---(1G eth)---                                                                        /---(1G eth)--- PC2
[SGE2000P]===(LAG1 2x1G cables)===[SGE2000P]
PC3 ---(1G eth)---/                                                                        ---(1G eth)--- PC4
 
If I send files from PC1 & PC3 simultaneously to PC2 & PC4 They don't transfer faster than if I I just use a single 1GIG Link cable
 
looking at the LAG configuration it shows both cables are connected & the LAG looks like it's working. But it really doesn't seem to be running at the expected 2GIG?
 
The LAG fail over seems to work fine if I remove either of the 2 cables from the LAG the link continues to work. (sometimes it will drop a ping when removing or readding a LAG cable)