This is a spelling question. Please leave a comment telling me what you reckon it is. Do you spell it as travelling or traveling?
I think it's supposed to be one L but I told my student last night there were two, just coz it looked right. But she studied English at uni and by the sounds of things she knows more than I do. My Times dictionary says there are two l's but my character geneology one says there's only one. The Times one was pretty cheap though. And I think there's some kind of oh what do you call it, "grammar rule" that I don't know about.
Competent or Incompetent English teacher: You be the judge!