When I started ML, I used to get seriously annoyed when I'd try to compile something and it'd just say "type clash".
Now I have mellowed. Also, annotating the types explicitly in the case of a type clash can be instructive as it usually reveals that you didn't write the function you thought you'd wrote...
c.f. http://ezyang.com/haskell.html#FixingTypes
Also, I submitted this before, but pointed at Odersky's comment. It made me LoL!11