Logic Express 8.0, should I re install?

I'm a little confused by your statement " I made the mistake of loading Logic on the desk top not in utilities."

First of all, Logic by default installs to your Applications folder, not to your desktop and certainly not to your Utilities folder. So for starters, if your Logic folder is on your desktop or somewhere else, you need to drag it into your Applications folder. Among other things, you can't install updates if Logic is not in Applications. After you've moved it try launching it to see if its performance has improved. You can also try updating it via Software Update.

Okay. When Software Update tells you that it can't find an eligible Logic Express application, that typically means that either the Logic folder is not where it belongs or it has been renamed. Make sure that the Logic folder (or package) is in your Applications folder (not nested inside another folder such as "Music Apps") and is named "Logic Express," not "Logic Express 8.1" or whatever. If it's not named properly SU won't see it.

If you are experiencing problems even after disconnecting the interface there may still be a driver conflict if you never uninstalled the M-A 410 driver. Also, check audio preferences in Logic . . . are you using your built-in audio output when mixing? . . . have you increased your buffer size to allow for smoother playback while editing? Playback will be glitchy if you try editing with too low a buffer size. You can lower the buffer size after editing to record with lower latency.

It wouldn't hurt to try deleting your LE preference file if you're comfortable with doing that. Go to your user library, e.g. Geo > Library > Preferences and delete "com.apple.logic.express.plist." Launch Logic after deleting this and it will simply create a new one. This often helps resolve issues.

I'm curious . . . do you use any other music apps, like GarageBand for example? If so, do you have audio issues with them also?

1) Do NOT delete ".app."

2) LE8 should run just fine in OSX 10.4.11.

3) You still haven't said if you've tested GarageBand to see if you experience similar problems. If you DO, that would tell you that the problem lies with your audio interface or core audio and NOT Logic. Troubleshooting will be a lot easier if you try another audio program instead of Logic.

4) Follow the suggestions in my previous post re: updating your M-A 410 driver and deleting your .plist file.

5) Try setting your I/O buffer size to 512 or even 1024 to see if playback is less glitchy. You can change it back to 256 again to record.