This may seem unfair or unimportant to some, but I know one problem we have here is English (or native) language skills. If I can communicate with my coworkers in plain speech, then it makes my job a whole lot easier, as we do a lot of phone conferences. It's very difficult to get what the customer wants--adding a language hurdle is one of those problems that I've found really slows down our development time. When his part of the project is mentioned in a meeting he does the same vapid nod, head-bob he does when you think he's understanding you... sigh...

We hire a lot of new guys here. All but one of our native speakers has been able to make significant contributions to our group(and the guy who didn't work out was a 15+year engineer who really should've retired 10 years ago...he's been moving from organization to organization, finding new and unique ways to do nothing for quite some time). It takes a while sometimes--sometimes just shadowing us, but it beats the shadow who can never tell me if they actually understood what I've been demonstrating.