MIDI Playback is erratic. How do I fix this

[TerminationShock]

Hi, I'm pretty new to using a real DAW and I'm loving it so far. The sound quality is great and I can feel how powerful DP is. There is still one problem I can't seem to find a fix for. When I play back sampled instruments like Cinematic Strings, or Berlin Concert Grand, they can't seem to stay on beat. Sure a few notes will start out on beat and then one note will play too early and the next one will play a bit too late. They aren't off by much but I can still hear it and its kind of ruining my mood.
What could be the problem. Could my computer be to slow, something about the MIDI clock not synced right or is there just some easy way to fix this that I'm missing?

With best regards from a newcomer,
Viktor IG

[stubbsonic]

It's hard to say what could be causing this. It could be lots of things, I guess.

If you are SURE you are inputing the notes right on time, and then play back is very different then what you recorded, there might be some input quantizing going on? Or perhaps if you are quantizing it, it might be shifting notes correctly but not giving you the results you are expecting.

[TerminationShock]

Yeah I'm pretty sure they are on the correct spot as I put them in manually and quantize them as. But even when Im just trying to input even eight notes they start to sound like they are a bit drunk. Swaying in time.