I'm sorry if I'm reporting this badly but I'm new to Webkit and new here.
When a word is underlined in red in the normal distribution of Safari control clicking the word pops up a menu which has at the top alternative spellings for the misspelled word.
This does not happen at all with WebKit. The only alternative is "Look up in Dictionary".
*** This bug has been marked as a duplicate of 12761 ***
Sorry, it's a known issue with the nightly builds--small price to pay for the latest and greatest WebKit.