I am having terrible luck with P4 C1 overclocks

[BurninUp]

I have a gigabyte 8ihxp 850E motherboard with RDRAM, I was running a 1.8a at 145FSB for the past year (45% overclock), I decided to upgrade - got a 2.4a (C1) from ebay - it would only go to 108FSB at any voltage.
Then I got a 2.8 533fsb C1 (again ebay), it will not run stable at 135 FSB (!!!) at any voltage.
Whats going on here?
Cooling is not a problem as I have tried intel and zalman 7000cu - same results.
Could I be getting modified chips? both these overclocks are DISMAL.
Anyway, do not buy these chips on ebay - cqause you can bet I am gonna sell these back

 

[onza]

don't go to ebay??

hehe, man.. maybe its just luck dude, cause i'm sure at least 1 of 2 you bought from ebay should OC well..

we'll see what the others have to say.

 

[WaTaGuMp]

There are never any gaurantees overclocking even if you get the best hottest overclocking chip out there. What about the memory your are using?

 

[BurninUp]

I am using 1066 RDRAM Kingston - it was at 145FSB for a year - I think it goes out at 147. This MB does not have ram timings. But I have a slight boost on volts to ram and agp - and up to .2v on processor.
So I figure I am limited to 145 FSB - and I wanted 3 gig plus, hence 2.4a x 145 would be = 3480 (thats optimistic haha), I only got 2.4a x 108= 2592
then I went for very conservative 2.8b x 145fsb = would have been 2800/133*145= 3052 (that should have been soo easy), I got nothing - not even 135 FSB.
I wonder if ebay is getting rejected chips ? because these are really poor chips.
The 2.4 was retail box - opened, the 2.8b was OEM.
I am saving about 40% from newegg prices - but not getting good results