Can someone explain this OC result with Celeron (I am a n00b)

I have a Celeron D 478, not sure which model but it's 2394MHz in CPU-Z.

My mobo's not really an overclocker I'm sure, It's a Foxconn 651M03, but it does have cpu clok adjustment from 133 up to at least 300 I'm sure.

I know it sounds silly, but I tried to OC my CPU clock by 1. Just 1. And it didn't work. I POSTed, and got into windows, but when booted up CPU-Z says my CPU speed is like 1800MHz! It decreased.

At defualt it's like this:

Core 2394.1
Multiplier 18x
Bus 133
Rated FSB 532

After changing my CPU clock to 134, the result is something like this in CPU-Z:

Core 1800
Multiplier 10x
Bus 100
Rated FSB can't remember but ~ 400 I think.

What am I missing?

By the way reasonn for just 1mhz OC is that my cpu's already 65c at idle, I think Its heatsink is dust clogged and maybe badly seated, I hust wanted to see it change a little bit, just for fun.

I guess the multiplier not being 10 is a point, I'll have to try again to see what the result is properly, I never wrote it down last time.

I don't know about the BIOS resetting, nothing else seemed to have changed, but I will double check that too. Why couldn't it handle a 1MHz increase?

I would not bother trying to overclock that Celeron chip by even 1MHz. It's pointless to overclock those chips. If I were you, I'd maybe keep the hard drive and any other CD/DVD drives you have... Pick up a new case, motherboard, CPU, faster RAM, and PSU. Even a cheap C2D Conroe would kill your Celeron right out of the box. A decent board can be bought for $100 or even less. Only do this if you're actually going to be using the processing power that you gain from upgrading. I upgraded last month from a Pentium D 2.8GHz to the new Wolfdale E8400 with a $90 Gigabyte P35-DS3L motherboard, and with the same memory and graphics card, this thing blows my Pentium D system out of town. It's like comparing a PSOne to a 360. That's the performance I gained.