Memory confugurations Mac Pro desktop

I'm hoping someone out there can help me:
I have an early 2008 quad core mac pro with 12Gb of RAM installed.
I took out the memory risers and DIMMS to give them a clean but did not take note of the DIMM configuration and now I can't seem to get the full 12Gb back again.
I have tested each RAM module by putting each one in slot 1A and booting.
All modules check out ok individually.
The modules are:
4 X Hynix 2Gb
2 X Hynix 1Gb
2 X QIMONDA 1Gb

What I need to know is what should be the insertion order, i.e. what pairs go into what slots on what riser.
I have also tried resetting SMC, but although I am putting them in pairs, when i do a memory check after bootup, it keeps showing some of the slots as empty.
When I power down and take out the DIMM modules, they are all hot to the touch, even the ones that were showing as empty. Maybe the memory check is lying to me?
Is there another way to see and test the amount of memory installed besides ABOUT THIS MAC / MORE INFO / MEMORY?
Maybe via a terminal script?
Would really appreciate any help.

Here you go:

Mac Pro: How to remove or install memory

- Nick

SOLUTION FOUND:
Ok, so fater much experimenting I have found the solution anyway, but will leave the post up for anyone else with the same problem:

RISER A:
|slot 1: Hynix 2GB|
|slot 2: Hynix 2GB|
|slot 3: Hynix 2GB|
|slot 4: Hynix 2GB|

RISER B:
|slot 1: Hynix 1GB|
|slot 2: Hynix 1GB|
|slot 3: QIMODA 1GB|
|slot 4: QIMODA 1GB|

Just to make sure that everything started at zero, I also reset SMC first by:

disconnecting the mains cable
holding the start button for 15 seconds
disconecting mains cable again
inserting memory risers as stated above.