If you were using the remote key maybe the battery was dead, but, the lock should have opened with the key. I believe Porsche wanted you to be able to get in with the key in case of something went wrong. It sounds like it did not lock properly...my suggestion is to remove the door panel and lubricate all parts that move. Lock mechanism, windows, etc. If you contact me personally, I will send you Diagnosis pdf which has the alarm system working with the keys, maybe it can help you. It's 38 megabits.
