AMD Duron 750 at 1.0 GHz??

I have an AMD Duron 750 MHz.
In my BIOS I can change the CPU Clock Frequency between 750 MHz and 1 GHz. The bus speed is 100 MHz when using 750 MHz clock, and when I select 1 GHz, the bus speed becomes 133 MHz. However, when I tried to boot with the CPU at 1 GHz, the screen had serious display errors, and everything was unreadable, included the boot screen (which was halted by the way).
I have one DIMM module of 256 MB and one of 128 MB, both are PC 100/133 MHz.

The question I have is, is there a specific reason why I can't use the CPU properly in the 1 GHz mode? Is the RAM causing me this problem? Why I can change the CPU frequency but without success?

The "CPU PnP Setup" page at the BIOS looks as follows:
----------------------------------
CPU Brand AMD K7
CPU Type Duron
CPU Speed 750 MHz *
CPU Core Voltage 1.600 V
CPU Ratio 7.5x
CPU Frequency 100 MHz
DRAM Frequency 133 MHz **
----------------------------------
(*) Available options are: 750 MHz / 1.0 GHz
(**) Available options are: 100 MHz / 133 Mhz
The rest of the settings are LOCKED.
The options above are the working settings.

I read a guide where I found that the CPU Ratio is locked by the processor itself, and to unlock them I have to make a bridge phisically over the Processor, using a conductive pen, (which I dont have and cannot get) so I would be able to select different Ratios. To change the Core Voltage, I also have to short some pins at the left of the CPU. It seems the only way to do it is using the conductive ink, a soldering iron won’t work because solder won’t adhere to the surface of the CPU. The needed voltage for the overclocked Duron is 1.75 V at least, which is the one that the new Athlons use.

The cooling is not a real trouble, since at my PC store I can get a powerful cooler which is used for the Duron 1GHz and that rotates at 6000 RPM, making a big noise.

If u wanna take a look, this is the guiude I found:
http://www.anandtech.com/showdoc.html?i=1345&p=2

It seems I'll have to open the CPU (as I do it almost daily...) and work directly over the CPU, a job that is not the most comfortable option.