[PROBLEM] My setup is very slow. SD card in cause?

[KingHeight]

Hi all,

I have installed Xbian 1.0 Beta 1.1 on a 8 Gb Kingston class 10 SD card.
However, things are painfully slow: a menu takes about 10 seconds or more to open in XBMC, "sudo apt-get install curl" has been running for 3 minutes and still isn't done...

I am suspecting this has to do with my SD Card but I read many times over that a 2 Gb class 4 is enough... So my 8 Gb class 10 should be more than enough, right?

What am I missing? Any SD card you would recommend without breaking the bank? I paid 10$ for that one and I'd like to keep it around that price even if it means going down to 4 Gb (I'm in Canada).

Thanks!