Icons disappear from Vista desktop shortcuts

[Warren]

I have a large number of shortcuts on my desktop and I have assigned
customized icons. For no apparent reason they will suddenly disappear. Is
there a setting somewhere that is causing my trouble ?

Thanks in advance

 

[Warren]

I should also add that I am displaying "medium" size icons on my desktop,
whatever that means in pixel size.

 

[Warren]

Indexing the area where the icons reside seems to have stabilized the
problem. )