I'm new here so I guess I'll just ask. I am currently running the aforementioned card and, sometimes the clock speed will drop to 648mhz and stay there, if I adjust it to 801mhz (currently running 800mhz and 1800 memory) and click "apply" it will go back up. I find this kind of annoying because it's a repetitive issue, and it doesn't happen all the time. Sometimes I can go a day or 2 without it happening, then it will do it.
 
Yes, I have "Maximum preformance" enabled.
Everyone knows the 460SE is easily capable of handling 800 core on stock voltages.
Yes my PSU can handle the card. I already checked this as well.
It does this WHILE gaming btw.

Did you check the option to apply clocks at windows start?

Yes I did. And I also have an update. It seems like turning the Voltage up to 1.0 and putting the core at 850 allows me to play for longer. Before I moved the voltage, playing Skyrim at 850 core would make the screen go back and revert my core to 648 after about 30 seconds. Just now I put it at 1.0 and I was able to play for about 10-15 mins before it did it. I'm so confused at this point lol...
 
Also, I would just test my stuff with oc scanner but it crashes at random times (between 2-6 mins). It's really annoying.
 
Sorry for all the side notes but, another thing was the voltage got turned down as well to .975 when the core went back to 648. Like I said all I have to do is change the core it to -/+1 and it goes back to normal.

Here is what happens when I run oc scanner. Finally got it to run for 10 mins.
Also I apologize if double posting is against the rules. I'm just trying to get help. 
Not sure if it's relevant but I'll list my comp specs under the pics.

 

 
Core2Duo E6600 (Not overclocked).
ASUS P5G41T-M LX Motherboard (LGA775 socket).
4GB Crucial Dual channel DDR3 1066mhz RAM.
OCZ 700W PSU. Won't let me post links but it's the only 700w psu on tigerdirect that's made by OCZ
EVGA GTX 460SE 1GB.
 
 

Keep upping the volts until stable.  For that core clock you will likely end up near 1.025/1.037V
 
reboot after every crash.

Oh ok. Thanks man. I'll update you in a couple hours after testing.

Oh, 1 last question. Can turning up the voltages to high damage the gpu? I understand going "LETS GO 2.0 VOLTAGE ALKDFAU" would destroy it but, if I just put it at 1.037 and left it there, even if it's .012 over the good voltage for my clock speed (assuming 1.025 is good) can it damage the card? Because I personally don't care about power saving.

Thank you very much Staypuft! After a few hours of gaming (Some MW3, BF3 and Skyrim) I'm still holding steady @ 850 core and 1.025v. God you can't even imagine how much irritation this relieves me of. I thought the card was going out on me or something. So once again my problem is resolved. And thanks alot again >.<.

Good to hear   You will be fine @ 1.025V

Yea I'm still running stable after another day of gaming. Now I need to acquire another 460se and throw it in SLI...
 
Also on a side note, nice rig.