Here's a problem I've hit in my doctoral research:
I have been looking for a way to resolve certain issues in AI, philosophy of Mind and Philosophy of Language. I thought that I could do this by using a combination of Saul Kripke's sceptical solution and David Chalmers' account of conciousness, particularly the idea of organisational invariance.

However, it's become obvious that Kripke's solution to the rule-following paradox is essentially functionalist, and is therefore prone to the issues of functional isopmorphs with no conscious or phenominal experience going on 'inside'. This is a problem because one of the sticking points in showing how a manufactured intelligence can 'mean' something by a certain word is that the entity might have no concious expereince. According to JR Searle (and I'm inclined to agree) this is a problem, because 'meaning' something by a word requires conciousness as nessecary but insufficient factor.

It seems a problem if even a sceptical account of meaning is prone to the same arguments that are employed against materialism and functionalism.