I really liked it (ducking now...), but I certainly understand why others didn't...
I knew a lot about the film before I went to see it though. I don't know if everyone else who has posted to this thread either knew that and still hated it (which is fair enough), knew that and just isn't mentioning it here, or didn't know that...
The movie was based on a book written in 1961 by the Polish author Stanislaw Lem. It was originally made into a movie by the Russian director Andrei Tarkovsky (possibly the best Russian director next to to Eisenstein) in 1972. A couple of things about the original - Tarkovsky wasn't making a sci-fi film...the space station and all of its weird affects was simply a backdrop for the other story. I would say the same thing about something like Apocalypse Now...if you've read Conrad, Vietnam is clearly just an appropriate context for this story tobe told...not the story itself.
So, if you were looking for a sci-fi movie and all that a sci-fi movie typically connotes, you were bound to be disappointed.
The other thing that probably bugged some people was the cinematic style. I can't find anyplace that says this specifically, but this was clearly a tribute to the original film adaptation. Tarkovsky has a very dream-like style, if you can call it that. The new version, with all the shifts in time, the music, etc was designed to replicate some of those qualities. That attempt could easily be construed as stylistically being "glacially slow".
Again, I certainly understand why some people feel that it was a bad movie and I am not trying to convince them otherwise. Only trying to make the point that it is hard to judge this movie in a vacuum.