Originally Posted by House

This won't be an issue at all. Even on flights to the United States, slight mistakes are permitted, such as getting the first and middle names the wrong way around, and even misspellings of 1 or 2 letters.

Using your example, in the last 3 months I have travelled on a wide variety of airlines, including LX, using variants in my name such as:

Joe Smith
Joe Clark Smith
J Smith
Joe C Smith

You'd only have an issue if the initial itself were incorrect (e.g. Joe F Smith) or a total mess-up of the name (e.g. Joe C Smythe).

There's a TSA discussion of this part way down the page I link to below. Given that TSA are typically stricter than other authorities I can't see you having any issue.

http://blog.tsa.gov/2009/08/secure-flight-q-ii.html