The photo on the ballast shows two CFL bulbs with 4-wires each. But your OLD CFL bulbs have only 2-wires each.
The ballast starts the bulb by heating its filament at each end. Your OLD bulbs do not have filaments, they are started with an OLD starter thingy that creates a high voltage spike.
Oh yes they do have filaments. They use a switch startler, like old fluorescent lamps do but it's built into the the fitting. The high voltage pulse is produced by the inductive ballast.
DO NOT overload a ballast with too many bulbs because then it will get hot and burn out or catch on fire.
Why not buy modern inexpensive CFL light bulbs that have a small electronic ballast attached to the base?
There's no danger of that happening. If you try to connect two lamps in parallel, the one with the lowest ionising voltage will start, leaving the other one off. It won't work but won't kill the ballast either.
i don't think you read through the listing page description:
(2/1) CFS16W/GR10q (2D)
(2/1) CFS10W/GR10q (2D) 4-pin lamp
- it lists CFT9W and 2G7 together. google'd it and found CFT9W are 2-pins, while 2G7 are 4 pins. maybe it can accommodate (2/2) same types or two CFT9W and one 2G7 (2/1), so it has a total of 8 wires??
No, it doesn't work like that. I suggest you read up on how fluorescent lamps work first.http://www.repairfaq.org/sam/flamp.htm#fbhttp://home.howstuffworks.com/fluorescent-lamp1.htm