I want to search for a file pattern in more than one directory. How I need to do that?

Here is the scenario:

I am having a directory structure like the following:
/log
...../20051001
..........ftp_server_20051001.log
..........ftp_down_server.log
..........ftp_up_server.log
...../20051101
..........ftp_server_20051101.log
...../20051201
..........ftp_down_server.log
..........ftp_up_server.log
...../20060101
..........ftp_down_server.log
..........ftp_up_server.log
...../20060201
..........ftp_server_20060201.log
...../20060301
..........ftp_down_server.log
..........ftp_up_server.log
..........ftp_server_20060201.log
...../20060401
..........ftp_down_server.log
..........ftp_up_server.log

I want to find out all the logs that start with "ftp_server" in the
year 2006 from the log directory.
Can some one help me with the command?

I used to try like: $ find . -name 2006*/ftp_server*. It listed only one
file information and quits with some error. I am looking for all the files

Thanks,
Ravi