I've noticed all my midi notes are always slightly before the beat, which makes quantizing and importing midi data to sibelius a real chore because I have to click nudge quite a few times and I don't know the shortcut, lol, and it just takes forever.
Is this as simple as lowering my latency to fix?
Thanks

Can you descibe your problem better?

If your midi notes are coming from your performance on a controller, then the fact that they are occurring before the beat is most probably because you are playing before the beat. The "midi latency" i. e. the time it takes for the midi controller to send a midi message to Sonar is usually very short, and would cause the note-on to fall after the beat if that were the only issue. A very large midi buffer might make this latency significant. Round trip latency, i. e. the time it takes for the midi message to get to Sonar and then through the synthesizer software and the effects software and back out of your speakers is the usual problem. If through practice, you have learned to compensate for a long round trip latency by playing early, then it might move your notes ahead of the beat. Usually that level of latency will provide a noticeable delay, and you will find your playing feels "off."

In any event, if you are just trying to fix the notes by nudging them to line up with the beat, you can do that by using one of Sonar's "quantize" algorithms to automate the nudging.

Well I don't feel off when I'm playing. I feel like while I'm recording on my midi keyboard, I'm playing dead on with the metronome click and I don't notice a delay from the time I press a key to hearing the sound from the soft synth. I must just be playing ahead then. Doh!
I don't have Sonar in front of me at the moment but I'll definitely have to find the quantize algorithm you mentioned. Sounds perfect.

maybe what your doing is starting to press the key on the beat, but the keyboard dont regester a note until you get to the bottom on the key stroke.

Are you using a combined audio/MIDI interface, or audio interface and keyboard connected by USB/MIDI? Whichever the case, you might try the alternate configuration.

Some interfaces seem to do odd things with MIDI timestamps that can cause an offset between MIDI and audio. You might try enabling IgnoreMIDIInTimeStamps in TTSSEQ.INI, and see if that thas any effect.

If all else fails, you can compensate for the offset by entering the appropriate Timing Offset value in Preferences (don't know the exact path in X1 off the top of my head).

Here's an exhaustive thread on the subject from a few years ago (has it really been that long?!):

http://forum.cakewalk.com/tm.aspx?&m=1301345&mpage=1

I'm using a line6 toneport ux2 usb interface and a novation sl mkII usb midi keyboard so they're both separate and using different usb ports. I'm using the asio line6 driver. I've been told the line6 toneport isn't that great of an interface so maybe it could be causing some issue. I'm going to be using it all day tomorrow so I'll play around with some of your suggestions.
Thanks

novation sl mkII

 
This will help you figure out what's going on because a keyboard synth can generate virtually simultaneous MIDI and audio output (usually within 1ms) that you can use as a reference for what SONAR records.
 
The first thing you'll want to do is check the audio latency compensation of the Toneport by running the free CEntrance ASIO latency tester (Google it), and comparing what it reports for a round-trip time with what SONAR reports. Then enter the difference in samples (CEntrance RT - SONAR RT) as a Manual Offset in Preferences > Audio > Sync and Caching (not to be confused with "Timing Offset (msec)" mentioned earlier, which should be left at 0 for the time being).
 
Then set up to record simultaneous audio and MIDI from the Novation using Local Control. Record a few isolated MIDI notes along with a drum sound or other synth sound with a sharp attack, and zoom in to see how the recorded audio and MIDI are lining up. Setting the tempo to 125 BPM (2 ticks.ms) or even 625 (10 ticks/ms) will make it easy to see how much error you're getting without changing you timeline display to milliseconds. And do this with the metronome off; we'll worry about that later. We just want to see the relative timing sync between audio and MIDI at this point, without regard to where it falls in the timeline.
 
If corresponding MIDI notes and audio transients are within a couple milliseconds with the MIDI being late (since SONAR does nothing by default to compensate MIDI transmission delay), then everything is probably copacetic with the basic audio and MIDI interface set up.
 
If not, let us know what you're seeing, and we'll go from there.

I noticed a strange feeling also ...i'm using the input quantize and it seems (same setting as sonar 8.5) that it's less smooth than 8.5 .....256 samples Vs 700

I'm a little confused about step 1. Everytime I run CEntrance latency tester, I get a different number of samples.

But if I do (1195x17.44)/769, I get 27.1 so does that mean I don't need to mess with the manual offset?