Voltage no longer allows for higher overclocking on ram

That RAM was factory-overclocked when you bought it. I'm not at all surprised it won't go any higher.
To avoid this problem, and give yourself some headroom, start with RAM that operates at its advertised timings on the JEDEC standard 1.8V.

Well, the timings weren't as tight as yours, but I "accidentally" oc'ed my Mushkin DDR2-800 to DDR2-960 and my system didn't so much as hiccup over it. I say "accidentally," because I'd forgotten to reset a ratio to keep the RAM at 1:1 when I oc'ed my CPU to 3.2 GHz. I'm pretty sure my RAM is still running on the stock 1.8V.

Yes G.Skill does make some good OC RAM, had my old stuff to almost 1066

a link to the RAM: http://www.newegg.com/Product/Prod [...] 6820231065
$99 for 2GB (2x 1GB)

*Edit* however with your config, the effect of RAM speeds is negligible. MORE RAM is better than faster RAM in your case. (unless you have the Nehalem, or an AMD proc)

Higher voltage doesn't always mean faster speeds or better timings for ram. Each stick is different. I had Patriot Viper ram that was rated at ddr2-1150, 5-5-5-15 @2.3V. But it would Always fail memtest86+. After much troubleshooting, I found that the ram passed memtest86+ 1150mhz, 5-5-5-15 @2.0V. So, for some ram too high of voltage will cause worse performance.