What I expected to happen was...:
The items being siphoned by the pipe would stretch into a uniform line, one item per hopper.

What actually happened was...:
The items moved at unusual rates, skipping some hoppers and overfilling others.

Steps to Reproduce:

The only way that I can think of reproducing this is to construct a simple version of my machine.
1. Build a row of 10 hoppers, all connected to each other.
2. Place a row of 10 vertical hoppers below them.
3. Place a row of 10 cobblestone along one side of the vertical hoppers.
4. Place redstone on top of the cobblestone.
5. Place a block of cobble with a comparator on it at the end of the final hopper on the top row, so that its output faces into the detecting end of the comparator.
6. Place a block in front of the comparator, and a redstone torch on its side, the side that has the cobblestone and redstone.
7. Place a repeater so that it is powered by the torch on a block so that it powers the redstone.
8. Place a row of individual containers (such as droppers, furnaces, or dispensers) at the very bottom, connected to the vertical hoppers.
9. Place 30 items in the very first hopper on the top row.