If for gaming, you will benefit for a new GPU first over the MOBO upgrade. If it is for anything else, you would just be better waiting for a complete system upgrade over upgrading the MOBO. There will be little or no benefit in doing so at this point in your build.
I would go with my second option to just wait for the whole system upgrade versus just a motherboard upgrade, as it won't really provide much benefit. However if you motherboard is defective, I would recommend the motherboard upgrade at that point.
Your are basically saying I would make no benefit out of the new mobo with DDR3 and PCI-e 2.0 compared to my existing mobo with DDR2 and PCI-e 1.1.
Shall I stick to my previous plan to buy a graphic card, I was thinking of buying HD 5670 or GTS 450.
Thanks ones again!!!