Actually lihyot is the technically correct pronunciation, but many speakers find it difficult to pronounce "h" at the end of a syllable, so they add "e" or "i". Those who drop the "h" just say "liyot".
FSI Hebrew clearly states that the infinitive is to be pronounced lihyot, but strangely enough it also states that the future tense will have an i inserted in all the forms (e.g. tihiye, yihiye, nihiye) except the first person singular, which is to be pronounced eheye. Inconsistency rules!