I wonder how "apple and strong beer" became "apple and strawber' "?

If this were a common mondegreen, you'd think PP&M would have corrected it by now, wouldn't you?

But it clearly says "strawber' " at PP&M's official web site, as well as every web site that posts their lyrics.

But then, you'd think they would correct the spelling "soalin' " to "soulin' ", too.

What's up with these people?