In my country, we don't get manga, so I often read them online. But some of their translations are so crappy. The correct meaning of the sentence is not grasped, the grammar's off and what not.
Anyone else with such experiences?

I agree with you -- Things often get lost in translation.

I feel so strongly about this, it's great that there's now a thread for me to rant on
So much is lost in translation! Especially many manga are translated from their Chinese translations, not the original Japanese because it's easier to get Chinese translators. Also something seems well-translated until you see just how varied the different translations are. Like can something really be interpreted in so many ways?!
Gakuen Alice was terribly translated, and there's this song by Hatsune Miku called Tsumi to Batsu (Crime and Punishment) which I love but I couldn't find a translation I was happy with. Neither could Nilu-chan and she ended up translating and subbing it for herself. (She's made loads of progress on her Japanese btw.)
Then there's also the thing that, some things can't be translated accurately into English because those words or phrases only evolved in that particular language.

Oh gods, that is so true.
(Nilu-chan's better at Japanese? Tell her to gimme lessons)
I remember trying to read the Kuroshitsuji manga and there was this line that was "Do you need saving?" on one site and "Should we teach him the proper way to beg?" on another.
Craziness overload.

Most of the sites that used to have the really good translations were shut down because the authors were throwing copyright everywhere on their manga, so the sites couldn't use the manga to sub and upload for free anymore. I have the same problem too and it really bugs me. Especially when I want to catch up on a manga and the translations aren't available. The shady translations don't really help me get anywhere with the manga, so I've resorted to watching subbed anime instead (until they decide to start taking those down and copyrighting everything for profit too...)

The struggle of not knowing another language is pretty tough

I know! I'm trying to learn japanese for that very reason but college is a b****