If you are praying TO President Bush, your father, or Dr. O'Neil, then yes. It's one thing to revere Mary, it is another thing altogether to pray to her. Prayer is an act of worship that can only be directed at the object of worship. By praying to Mary, I believe that a person crosses the thin line between reverence and worship.
Can I direct my prayers to Jesus or to the Holy Spirit? I believe so since they are part of the Triune God whom I am worshipping. Neither Mary nor the saints are.
It seems that there’s a fundamental difference between how Catholics and Protestants treat prayer.
To Protestants, prayer is equivalent to worship.
To Catholics, prayer is not quite the same, in that is merely ‘speaking spiritually’...or something to that degree. Prayer can be a form of worship, but not always?
Sorry, but your definition is a little on the narrow side. The definition includes asking in a humble manner. See the definition from the Merriam-Webster Online Dictionary:
Main Entry: pray
Pronunciation: \ˈprā\
Function: verb
Etymology: Middle English, from Anglo-French prier, praer, preier, from Latin precari, from prec-, prex request, prayer; akin to Old High German frāga question, frāgēn to ask, Sanskrit pṛcchati he asks
Date: 13th century
transitive verb 1 : entreat, implore —often used as a function word in introducing a question, request, or plea {pray be careful}
2 : to get or bring by praying
intransitive verb 1 : to make a request in a humble manner
2 : to address God or a god with adoration, confession, supplication, or thanksgiving
This is also where we get the old English word "prithee"... "I pray thee." Even the Latin word "ora," which is also translated as the verb "to pray" can also mean "to speak."
"Prayer" is simply making a request. In fact, in archaic English (still used by lawyers!), they're the same thing, which is why you "pray" a court for redress. (No, you are not offering idolatrous worship to the judge.)
In some other languages, the word for "pray" and "ask" are still the same.
Offering sacrifice is intrinsically an act of worship, and can only be offered to God. That's why Catholics don't offer any sacrifices to Mary, and that's why we rejected as heretical an obscure Arabian sect (called Collyridianism) which did.