Possible Clues:

• Problem an angler might have?
• Those involved in a cast might want them to open up - creating a potential difficulty
• Something likely to prove awkward
• Source of problems
• Unforeseen difficulties
• Touchy situation
• Bird's convenience food that may pose a nasty problem
• Robin's instant meal? Potential problem
• Complicated problem caught as from now possibly
• Woman's frock being shortened could develop into a problem