I have a really common first name (four in my primary school class), a fairly well known last name, and DH has a really common first name (though it's Welsh and we live in England) and a last name that must be in the top 10.
We still get people misspelling all four names. I can't think that anyone has misspelled all of them on the same document, but we've had up to 3 on the same envelope. Including from family (I think one family member who shares my last name spelled all the other 3 wrong).
We also get people who can't pronounce his first name (quite often, even in the UK, though it is one of those Welsh names suffering from vowel deficiency) and also who think that his spelling of his last name makes it pronounced differently to the alternative spelling (it doesn't, they are both pronounced the same).
My first name has a longer version too so that confuses people, who can't spell the longer version, or even pronounce it. Think someone called Eliza short for Elizabeth and them pronouncing Elizabeth "E Lyza Beth" or more like "ElizaBeeeth". So mis-pronouncing my full first name to make an impossible pronunciation that nobody has ever heard of, rather than a very common if slightly longer girl's name.
I had an official email come back recently with something like Lisbeth - wrong first letter, completely wrong spelling - from someone who had an official document with the right spelling right in front of them. In the same email (in reply to one from DH's email address with his name correctly spelled in the header) his first name was also misspelled.
So it really doesn't seem to matter how common your name is.