Input monitor hiss/latency issues

Right, another noob question, I am getting rather frustrated.
This is driving me insane cos I don't seem to be able to do basic set up!
 
All I want to do is plug an instrument into my 'input' jack on the computer, hear the instrument, and monitor it with effects etc.
Here is my problem.
I am using an installed ASIO driver.
I have connected my piano to the computer via the line-in on my computer.
I have set Sonar up so that I can hear the piano directly, and there are no problems with that. I have solved the 'echo' problem when using input monitoring, but the latency is totally unacceptable (even though the user guides say it is negligable, it isn't)
I have tried every setting I can think of in Sonar, and the ASIO driver, to correct this latency but nothing is working.
 
So I went back to using the WDM driver, and set Sonar up to use that, as this is also a suggestion in the guide.
I have no latency problems, but when I turn on input monitor the sound is distorted, and the effects I have set up for the input don't work properly and are distorted.
Now I know that in the guide it says 'When you use input monitoring, make sure that the track you’re playing through uses the same audio interface (sound card) for both input and output. Using different audio interfaces for a track’s input and output can produce distortion during input monitoring' so I have tried every combination of available input/outbut settings within the track to no avail.
 
My soundcard is Realtek HD Audio Output, I'm using Windows XP 32bit.
 
I can't find anything further in the guides to rectify this.
Can anyone help?
 
Cheers, Mark

Hi Greg,
It's ASIO4All.
I use the line in jack for my instruments.
The only distortion I am getting is when using the WDM driver and selecting 'Input Echo: On' so I can hear the real-time effects.

If I record while hearing a small amount of latency will that transfer to my recording?

By the way I have 1.99 GB of ram

Mark

Yeah, I changed as many settings as I can think of, and no improvement. I know the performance of the standard sound card isn't great and a little bit of latency is to be expected, but the latency I am getting with the WDM driver is too large, and the distortion from the ASIO driver is unusable.
 
I could record directly without input monitoring, but then why have an input monitor function is it is unusable?
 
To be honest, this is pretty much all new to me so if I change one setting I have no idea how it affects other settings, but I'm starting to learn.
I am looking at other soundcards, but I'm not sure which one would be best.
 
Cheers
 
Mark