I would guess that you have some problems with a plugin or script. Try to disable iPhone.dll by renaming it to .off or similar.
I actually had similar problems as you, I ended up with renaming my whole Plugins folder to PluginsOLD and then reinstalled MM. Worked great.

Also, compact your database "File->Maintain Library->Compact Database" it makes miracles sometimes.

JActon wrote:MM is very slow to load, scans files each time, regularly locks up.

Is my library too large?

28,000 tracks isn't large relative to some users here. It could be that your install is corrupted in some way as the symptoms you describe are not normal, other than possibly the start-up scan, which you have disabled.

Duplicate files - off.
Start up scan is off.

I'll try the mouse thing.

Shouldn't be my PC - Duo core 2.33GHz, 2GB ram, GeForce 8800 512 - the music drive is just that, defragged and only for music.

I'll have a play around in safe mode and Admin mode and see what happens

You can always disable the start up scan if it takes too long for your liking.

Pc might be slow but have you turned off Duplicate File search from the Options - that feature when turned on slows down media monkey a lot.

Another thing to do when loading folders is to place the mouse on the "Library" in the tree and then do load folders from File menu.

I have noticed its slower if the mouse is placed somewhere else when the load is happening (for instance on Artist & Album)

MediaMonkey I think does do a quick re-scan on loading but I have more files than you and mine is fine so it might be your pc is slow (what spec is it?).
Also defrag your hard disk holding the music.

Just started to use MM 3
file library nearly 28000 files, mainly MP3, a few ape and flac
total size 220GB
turned off album search, file monitor, etc

MM is very slow to load, scans files each time, regularly locks up.

Is my library too large?

TIA