It is possible that after patching your client to v1.582, you won't be able to play anymore. At the moment there has been several reports regarding this issue.

Problem: After patching your client to 1.582, the client crashed on loading screen.
Solutions: A few possible solutions are posted here. viewtopic.php?f=15&t=7509&p=37999#p37999
-> I'm still looking for the general bug, why and howcome. How to fix this etc.
I'll post the solution once I found it.

Note: This problem seems to be only on Operating Systems Windows XP sp3.

This sollution has been confirmed as an accepted solution.

Repatch your client starting from SCRATCH. That means that in your server.ini on "version=xxxx", you have to change it into: version=1501
This will patch the whole client from the beginning.
Note: that the first 30 patches needs to be manual patched.

viewtopic.php?f=15&t=7667&p=38783