What are your biggest consulting challenges?

On this blog I share my experiences, observations, and lessons learned as an independent consultant -- interspersed with questions for my readers.  Even though I've been consulting for almost 17 years, I can't begin to claim to have a lock on the knowledge of how to run a consultancy.  Like anyone else, I'm still learning.  In fact, the more I learn, the more I realize how much more there is to know about this business.  As Ben Franklin said:

The doorstep to the temple of wisdom is a knowledge of our own ignorance.

Your comments on this blog have taught me more than I would have thought possible.  Whether it's by challenging my ideas, confirming them, or just getting me to think through something I hadn't properly considered, you have helped to make me a better consultant.  I hope to return the favor.

With that mind, I'd like to get your input on subjects for future articles.  What are the challenges you face that you'd like to see discussed here?  What problems do you deal with on a daily basis?  Are there creeping issues that you can almost see at the periphery, but you try to ignore -- even though you know that one day you'll have to address them?

Just to get your thoughts flowing, here's a poll of some of the more common consulting challenges.  Please feel free to discuss more than just these.