I find it very hard not to use am in a sentence, when strictly speaking it should be I'm. Example: 'I'm going to France tomorrow and am determined to have a good time.' It usually happens when the 'I'm' is sandwiched between words rather than when at the start of a sentence, and is said more loosely in natural speech, . It looks rather stupid when my attention is brought to it, and I'm not sure I've come up with a particularly good example there. Maybe it's only be that does it??