Some people have fresh struts that will push the hatch all the way up as soon as you hit the release or turn the key in the taillight. They lose internal pressure over time though, and it's worse in the cold.
New struts will fix it, they're not hard to replace.
It may depend on the brand or something... my hatch struts were replaced in 2001 and I still had to lift the hatch partway before the struts would push it all the way up. I've never had the hatch go up on its own.
^^ second that, got a handle piece of wood back there to hold it up. Whats a good outlet for new struts? Honda still make OEM replacements or is there an aftermarket strut with the same style attatchments?