I have installed a beta of MySQL 5 to play around with and I can connect via a PHP script. This is interesting as it will work using mysql or mysqli functions. I also have 4.1 installed and it only works using the mysqli functions. In addition, I have 4.0 installed too. I have it setup where I can start/stop the service for each server and I only have one instance started at any given time. I have the MySQL Administrator as well as EMS MySQL Admin installed and when either app attempts to retrieve the table data for a selected db, they stop the MYSQL5 service. Can I consider this behavior as part of the beta MySQL 5 or perhaps the apps are not able to work with it yet?

It is a bug in 5.x, you can use show table or show create table or desc table I believe or all will crash the server.

I run 5.0.2-alpha, which does not crash or return a reply, but simply consumes 100% CPU when a "SHOW CREATE TABLE" or "DESCRIBE" query is executed. The thread that executes it becomes unkillable, but the server continues to work.