Ok I just got this new 5600+ 2.9 Brisbane 65nm I want to overclock.  Im using an Aquagate S1 water cooler.  
My first overclock
 
3.12GHz OCCT stable 1 hour
multiplier  14.0  
buss speed 223.0 MHz  
core voltage  1.400V
HT Link 892.2 MHz
ram set to 892.2MHz
 
Ok my next over clock didn't work but I need to figure out what the max core voltage is and if I add more will I be able to maybe make it stable.   Ill be back in a little bit and tell you what happens.

Your overclock probably didnt work because either your motherboard cant handle all the extra HT speed, or your RAM cant handle being at 892mhz. Bring  your RAM multi down that should help.

I thought 892.2MHz for HT Link is quite easy to do?

so did i but any thing over that and it fails in OCCT 1 hour test  I can probly get it higher by going lower on the fsb but im not sure what is better since the ram and the HT Link are running the same speed.
Ill go drop the fsb and see if I can get the HT Link any higher and keep it stable.

Yeah I lied the HT is fine at 900mhz. I think its supposed to be 1ghz or something, watch it if it goes anywhere past that. Also, the Athlon 64 X2 don't seem to like going much past 3.4ghz, from all the reviews and forum posts I've read. You might be able to go higher because you have water cooling, but your RAM or motherboard could be holding you back. Definitely try and take your RAM speed down closer to 800, and its perfectly ok to be a little below 800mhz.

Ill  try  13X 247 and drop the ht link to 4 and the ram to ddr2 667 and see where that gets me.

ok 13X247 didnt work at all but im trying out 13X240 now that gives me  
 
3.12GHz  
multiplier  13.0  
buss speed 240.0 MHz  
core voltage  1.400V
HT Link 960.0 MHz
ram set to 960.0MHz  
 
Im running OCCT on it now and its 10 min in to it and so far so good.
any one know the max cpu voltage for a 5600+ Brisbane 65mn?
 

lol that didn't work either.  I think Im just going to have to go with the lower clock and be happy with it.

 
3ghz is around the max average oc for any AMD (90-65nm) anyhow

I'm in the process of OCing my setup, which may help you.
 
AMD Brisbane 5400+ 2.8
MSI K9A2 CF version1
GSkill DDR2 800mhz
Rosewill 550W Sli ready  
Zalman 9500A cooler
 
I have it stable currently at:
CPU is at 3.2ghz, (229x14)  
HT- 916.1mhz 229x4  
CPU volt- Bios reads 1.48, CPU-Z reads as 1.45
 
Most important thing is your cooling and RAM. You have water cooling, so that shouldn't be an issue. To eliminate ram as the cause, set your RAM down, to 800 or below, you can always OC your ram back up, once your CPU is stable. My memory is currently at 900, but during testing, it was around 750mhz.
 
Brisbane have a faulty temp sensor, so programs like Core Temp, Speedfan, even AMD's Overdrive do not read it correctly. The way I'm going about it is, check your temp in the BIOS. For my reference it is normally at 35C-38C. I use 40 just be pessimistic. I launched Core Temp and use the highest temp reading. In my case it is at 20C. Under load with Prime95 it is reading at 38C. That is a difference of 18C. I add 18C to my BIOS reading of 40C to get a rough temp of 58C under load.

is it safe to have the cpu volts at 1.45?

Base on my non scientific research of other forums, it appears many have had success as long as it is under 1.5 with Brisbanes. I can't really say it is a definite that it will be safe at 1.48, but you should use your own judgement.
 
I really don't mind in my case, the processor was purchased for under $100, and if it happens to croak early, It'll give me a reason to pickup a Phenom.
 
On another note, I did manage to get my setup up to 3.313ghz, 265x12.5 while experimenting. Ran Prime95 for over 1 hour without any errors, however temps were at 68C to 70C with 1.51V.

I had mine set at 264x12.5 I believe which gives exactly 3.3ghz.  I was running 1.45 and temps were not much different than they are now with 1.35 at stock on a 5400+ brisbane.  I am using the CoolerMaster GeminII and seems to work great, especially  for the $15 that I got it for.  Stable as can be and I could get it higher but in PCMark the audio encode would fail for some reason with the realtek driver screaming problem.   Any good board should take the brisbane to 300-330 Mhz FSB most likely as I've had mine up to around 320.  With My 4000+ I just set it at 1.45V and 300x10 which gave me a perfect 1000mhz DDR and some 10,000 to 11,000Mb/s memory bandwidth in sandra.  Temps on overclock at 1.45 would usually top out at just below 50'c running any benches.  Yeh even though the HT says 200,400,600,800,1000 it is really x1,x2,x3,x4,x5.  So say you have it FSB at 300 then you would want the x3 or 600HT.

Really, 3.12 vs 3.2? You're not going to be able to tell the difference and your processor will probably last longer at the lower speed. Actually, 3.12 is a pretty good overclock (I'm running my 5000+ BE at a similar speed). Congradulations.