[dfbennett]

Hi all,
I've had a problem occur twice in the past 24 hours running 10.0.3 on my G4 Sawtooth 350 with 256mb of ram. I was using like 3 apps and I went to launch another and it never launched. The icon just sat there with the flashing arrow underneath it. Eventually the arrow stopped flashing but the app never launched. I brought up the force quit window and it didn't appear even though it appeared in the dock. I couldn't even realaunch running apps or restart from the menus. The only way out is to hit the reset button. Some have said that they had the top command running and when this occured there were like 4 Window managers running. I can only assume this is somehow related but I have no idea. It's really annoying considering X is supposed to be stable. Oh well at least I can save my work before I have to hit the reset button

[malvolio]

I've had a similar problem a few times, and it seems to be memory-related. What was happening in my situation was the infamous "disk thrashing" as VM paged out to my hard disk. A restart wasn't necessary, just lots of patience.
Are you running Classic when this happens? I discovered that the Classic background printing extension tended to "go crazy" on my machine, so I disabled it and the problem hasn't recurred.

[Earth Mk. II]

I've had the same problem on occasion too... it usually occurs when Mail.app is running and is fixed (for me) after Mail.app is closed. That's my experience with it anyway.

(2x G4@450, 192 MB RAM... and yes, top reports several window managers open - all at idle)