zenin if i may suggest just totally do a fresh install of shop. if that doesn't work then you know that the php isn't messed up. (unless if you get install errors or uninstall errors)
if it still doesn't work there may be problems w/ your host. ask them for support if ^^ doesn't work.
and yeah guys i've been registered on his forum for a while and i'm getting the same error as a member too, any link you click while you're in the shop gets a similar error on a line close to the other lines stated in the errors. so if you can help in any way please do
i noticed that these errors first occurred when zenin switched hosts for his site.