I've never had any problems hauling my bass guitar around Europe - it either goes in the cupboard or across the top of the cases in the overhead bins. I do make sure I'm in the boarding queue early on these occasions.

The biggest performance was a CdG where the French security swabbed it took a manual note of all my personal details - Lord knows what for and it took ages to do.

There's an amusing (although not for the traveller) ditty on YouTube somewhere about a guy who put his guitar in the hold and it got broken - "United break guitars" I think it's called.

Andrew