YES!!!!  I ALWAYS got them.  I would think it was sugar, salt, sour or even the toothpaste I was using.  I spent a LOT of money on natural SLS-free toothpastes too.  Then when our son was born, HE would not only get the canker sores, but the big, white and painful aphthous ulcers in his mouth before he was even a year old.  Upon asking the Dr., he informed me it was a virus and try not to kiss your bayb!  Ya right!  My son and I just dealt with the ulcers in our mouths on a regular basis—and they would strangely always seem to appear really badly when we would travel and eat all that junk food, drive thru food Wink  It wasn't until Diagnosis/GF in 2005 that those 'viral ulcers' disappeared—totally!  And we do get them again with trace contaminations and regular contaminations.