My site is slow and sometimes goes down, but who's fault?

[Daem0n]

Ok so here's the deal. I'm running a blog site with Wordpress software and a few plug-ins, nothing crazy. I registered this domain a long time ago at godaddy (don't ask why). I'm currently using hosting at site5.com. Site5.com seems awesome but I can't really tell because of a few things... People viewing my site say it's sometimes slow. I can't really tell because I'm currently in Japan so if it's slow it's because of the routing here. When I check it on websites that check loading time, they say the load is average so I'm not too worried.

The thing that has me more worried is that my site goes down frequently. When I go to godaddy my account is fine and the domain seems fine with the right DNS servers assigned (the ones at site5.com). When I check my server status at site5.com, the server is up and I can access my admin account, etc. So, where is the problem? Who's fault is this? Can you guess? I have no idea. Thanks for any help!! -Joe