I tend to use minified libraries (JQuery, effects libraries, etc), but unminified application-specific code. Been burned too many times having to root out some obscure error on the live server, and not being able to do so because of minification.
However, I've never had a problem in the cases where I have indeed minified unsemicoloned code. Has anyone else, or is the problem just theoretical? If others have encountered an actual problem, I might have to rethink this strategy for larger codebases.