Never split an infinitive. The fact is, some infinitives beg to be split.
Consider this sentence: Our CEO expects to more than double revenues this year. Try rewriting it so as to eliminate the split infinitive; there’s no way to do it without losing the precise meaning of the original.
Here is another example: We are trying to immediately solve the financial mess that is bleeding the organization. Although you can rewrite this sentence by placing immediately at the end of the sentence, the intended urgency is lost.
With split infinitives, the best bet is to steer a middle course. If you can avoid a split infinitive without altering meaning, introducing ambiguity, or interrupting flow, you should do so.