This gets stranger, I have the same full E17 installed as a virtual machine in my VMware Workstation 7, currently running on a Win7 Ultimate computer so I installed Picasa from Synaptic exactly the same as my stand alone computer and lo and behold there was the Picasa icon right where it should be. I have checked both systems, they appear to be identical, both installed to multiple partitions, a / partition, a /home partition, a /mail partition, a /storage partition, the only variation would seem to be that on the virtual E17 I have a second /storage partition and on the stand alone a /tmp partition.
One thing that does seem odd is that when I check my home partition it is shown as Root/home/ray (using Dolphin) no Thunar etc on the stand alone machine but using Thunar in the virtual machine shows it as the normal /home/ray
Yikes this is very confusing for us oldies.
Ray