It has come to my attention that some of the members of the kin are experiencing regular crashes while being in highly populated areas of the game (21st, Dolven-view come to mind). Here are a few links to the official forums that describe a possible fix.
http://forums.lotro.com/showthread.php?t=224001
http://forums.lotro.com/showthread.php?t=250869
This is a fix for people with 3-4 gig of memory and 32-bit OC. Basically what this does is it frees up more memory for the game and leaves less for system processes. I have 4 gigs and i have set this to 3072 which leaves me with 1 gig for system processes. Turbine has their own solution for this, but I can hardly call turning down the settings a viable solution.
This isnt a 100% fix, it may or may not work for you, but i believe that it is worth a shot. You can always change it back if it doesnt work or if you start experiencing issues/slowdowns with other applications.
Personally, I havent crashed since I tried this, and I am not experiencing any issues outside lotro. I know that Mandy tried this fix as well, not sure if he still does but he sure seems to be crashing less.
Oh and… If you decide to do this, you're doing this on your own risk. Im gonna be not responsible for any issues you may experience because of this fix.
~Elo