Duplicate/Copy&Paste errors with Samples on Grid

[Kikonda12]

Hey everyone,

I'm having an issue with fitting samples to the grid (.wav files of just a snare hit or a kick hit). When I paste them out by clicking on the Grid, they generally always fit to the Grid. However, when I highlight a whole section that is fit to the grid, and then Duplicate or Copy/Paste, some of the samples will sometimes slide a little early or a little late of the grid.

Here is a screenshot showing how far off they slide (it's only a little):
Zoomed in: http://www.freeimagehosting.net/6h9p4
Not zoomed in: http://www.freeimagehosting.net/yggor

Why is that happening? Does anyone know how to fix it? If I use Quanitize to Grid, there end up being little gaps which I am trying to avoid, but maybe that's the only way except for checking every sample manually?

I'm working in Absolute Grid mode, the tracks are set to Tick, and I've been resizing the samples to fill exactly the amount of time they are taking up.

Thanks so much

[Stig Eliassen]

What you are seeing is called Sample Rounding. From the Reference guide, page 774:

Sample Rounding and Edit Operations

When audio material in Pro Tools is sample-based, some amount of sample-rounding may occur with some edits when the Main Time Scale is set to Bars|Beats. This is most evident when you need audio clips to fall cleanly on the beat (as when looping) and notice that the material is sometimes a tick or two off. With a few simple precautions, this can be avoided.

To ensure that selections are precisely aligned to the grid for looping, copying, duplicating, or repeating, consider the following:

- If you use the Selector tool, enable Grid mode and select the appropriate grid value (such as sixteenth notes).

- For the greatest accuracy, type the selection Start and End points in the Event Edit area.

- Do not select the material with any of the Grabber tools (or by double-clicking with the Selector tool).