Be sure to append the port number after the IP address or server name, so "..IP.123,1599" or "WS0x,1599".  You'll also need to append the port no to the DB address in web.config

I've found that I like using the MyLittleSQL tool WSS provides through HELM since I don't have Ent Mgr 8 - you can do all the basic and intermediate stuff with it like manage SQL users & permissions, SPs, etc.  I use it exclusively now.

If you haven't setup your DNN DB yet try these steps:
1) Create your DB & db user through HELM control panel
2) Modify the db user permissions using Ent Mgr or MyLittleSQL
3) Run install.  This should work fine.  If you get any errors ask WSS to double check all the permissions.  I've also used the DNN install script they provide - just create your DB, run the script, upload your custom web.config & run install - super easy.

I really like WebSecureStores - I've been with them for over a year and for $39.95/mo get everything I need.

JP

Since I don't have access to EM right now I'll take a shot:

Be sure that if anything says "initial catalog" that's where to put the "name" of the DB, not the address (you can see the name using Helm --> DB).  As long as you have the IP, port, initial catalog (name), user name & password you should be able to connect via EM.

If you haven't tried yet, try the MySQL tool in Helm - you can see all the tables etc, but more importantly, you can use this as an easy way to verify you're using the correct connection info, since you'd use the same info for EM.  If you can't connect via this tool then you probably don't have the correct connection info.  Verify your connection info by logging into Helm and looking at the DB IP & name - the last time I setup a new WSS account they sent me the wrong IP & DB server name - I couldn't connect untile I found the error.

For User Level select "Advanced" and for level password use "password" (per KB help).