I don't have CF, but I remember when I'd get sick -- I'd be perfectly fine, feeling great, hanging out with my friends, next morning bam! High fever, sore throat -- bleah!
Not that DS has had very many ear infections -- think he's had 3 and a couple sinus infections. I have noticed that when he's been given that pink stuff -- amoxycillan (sp) instead of augmentin, I end up going in after 10 days for something stronger. I've learned to ask for augmentin and it usually does the trick. And I don't think this is a CF thing. DH's side of the family has always had problems with ear infections, tonsil, sinuses etc. and I was talking to one of his cousins who used to send her kids to DS's same peds doctor when they lived in town and she said "the one thing that drove me nuts about dr. x was that the only thing that would get rid of ds's ear infections was augmentin and he's always prescribe amoxycillan first and I'd have to take DS back in" So two doctors appointments and two extra weeks on antibiotics.
DS's doctor told me before that he's going to get sick -- regular childhood illnesses -- colds, stomach bugs.... The key is being vigilant so it doesn't turn into anything worse. And make sure that if there's a cough associated with it -- beat him more often -- "beat that cough right out of him". Liza