Hi, I'd just like to say... I was crashing every time I went into edit. I build and it was getting really annoying. I read a lot of different things on how to fix it and this is how it worked for me.
Clear cache ( edit- preferences- web)
Re-start second life only up until the log-in screen...then drop your screen and clean up disk space (on my pc windows 7, go to control panel-performance and maintenence- it should pop up at the side bar - clean disk space , this should take a couple of minutes)
Log into second life as normal
I also removed all mesh items I was wearing...in my case hair