Oh all the time. I have a couple of allergies which require me to constantly put in special orders wherever i go, and it gets botched at least 50% of the time.
The funniest recent incident: a guy was leaving our office at work, so our whole team took him out for lunch on his last day. There were about 12 of us who wound up at this little chinese place.
Admittedly, it was a busy lunch hour, but we all put our orders in, and then we waited.. a full hour went by, and nothing. Another 15 minutes, and FINALLY we said something.. Turned out they had accidentally prepared our's "To Go", and it had been sitting on a counter for the past hour getting cold.
One of the members of our group was asian, and he absolutely went off on the waitress in chinese.
Then when our food came out, one of the girls had asked for a specific dish and that it "not be spicy".. They misunderstood and made it SUPER spicy.. She started bawling her eyes out after one mouthful, it was so hot.
Fun day, that one.