Ok, to even more increase global head-shaking in my behalf :D

Fixing the broken link just seemed to be the issue here. I had removed
all squeak packages for ubuntu before and installed the squakland
package after that, leaving many dangling symlinks. Installing squeak
packages again I thought the problem was a bad link leftover. Testing
*from a shell* worked. But what happened is, that the newly installed
packages changed the way how squeak images are started *from the
desktop* again. I had changed the launch method to squeakvm with
buttonoptions once (see why [1]) and now the squeak launching script was
executed and instead of the squeakvm the squeakvm launching method was
used. Now double clicking on a squeak image resulted in starting the
real vm like "squeak -vm-display-x11 -swapbtn sq3.9-7067dev08.01.1.image
squeak.image". The additional squeak.image made CodeLoader raise the
exception.

Pooh!

Now beyond shooting myself in the foot with this, wouldn't it be a nice
feature to have the vm answer a default sources directory (via some
vmparameter) and make the image look for sources files in that directory
instead of having many copies of or symlinks to sources files all over
the place?

Alex

[1] http://tinyurl.com/337ro3