I experience quite some "serial mangling" with the Zedboard. I'm using the USB cable that came with the board, and am running Ubuntu 11 on my PC, using minicom to connect to /dev/ttyACM0.
When copying small amounts of text to the terminal on the board, I often get "mangled" bits, causing the command to be corrupted. I have not seen this with other boards.
For example, I copy this:
mmcinfo;fatload mmc 0 ${kernel_addr} ${kernel_image}
But what the terminal echoes back is:
mmcicfo;fatload mmc 0 ${kernel_addr} ${kernel_image}
or
mmcinfo;fmtload mmc 0 ${kernel_addr} ${kernel_image}
The changes are random, but quite often. To generate these examples, I only needed 5 copy/paste attempts.