Tedious Curiousity

I'm curious to know what parts of making a website do people find most tedious, frustrating or time consuming - and perhaps how many hours are consumed doing this part.

As a kicker, I find doing css the biggest headache - and especially doing the css for the menus... to get them to look/perform as imagined. And I have spent literally months of time learning css, and still feel I have no clue!

Two centses appreciated.

For us here: Most tedious part is the information architecture designing phase. It takes us about 2 weeks or more to build a sites structure. 2nd most tediuos thing is waiting for the content from clients. This takes sometimes years!!!