It seems the jumpers you speak of, simply do not exist! Take a look at the <A HREF="http://www.via.com.tw/en/Digital Library/prhome_c3il.jsp" target="_new">VIA C3™ Image Libary</A>, scroll down to find your mentioned processr - which is <b>VIA C3™ 800MHz</b> and from the <i>VIA C3™ 800MHz Still Image Rear View</i> category select <i>High-res</i> (quick-link <A HREF="http://www.via.com.tw/en/images/C3/C3_800MHz_Back_H.zip" target="_new">here</A>).
Now show me, from that high-res image, the jumpers which you speak of. You may wish to double-check that the jumpers are in fact actually on the motherboard.
Perhaps you <i>know what [you are] doing when come to oc'ing generally</i>, however we all make our little mistakes. I am no expert, and I make blinding-obvious mistakes sometimes!
Why don't you give us the brand and model of your motherboard. This information can be obtained in minutes by either checking for screen-print on your motherboard, or using a tool such as <A HREF="http://www.hwinfo.com/" target="_new">HWiNFO32™</A>.
Can I ask why you chose to overclock such a processor BTW? Albeit cheap, what exactly would you succeed in by managing to overclock it? It's hardly going to play graphic-intensive games very well, overclocked or not!
I'm not criticising you for overclocking this particular processor. I <i>was</i> tempted to do so myself, purely because of the cost! So what if I fried it? It's only £27.50 (<A HREF="http://www.dabs.com/products/prod-info.asp?quicklinx=16WS" target="_new">Via C3 800Mhz 64KB</A>). But at the end of day, I knew it wasn't going to be upto much horsework so I scrapped the idea. It was just one those "should I, because I'm bored" ideas whizzing around my head!
Anyway, I hope to get your motherboard brand and model soon!
<font color=orange><b>Some people don't realise that a mere two hours backing up their data is far quicker than redoing all the work again!</b></font color=orange>