it's then you stumble across such an error message:

java.lang.StringIndexOutOfBoundsException: String index out of range: -89
 at java.lang.String.substring(Unknown Source)
 at java.lang.String.substring(Unknown Source)
 at ZeroGla.a(Unknown Source)
 at com.zerog.ia.installer.util.magicfolders.JavaHomeMF.a(Unknown Source)
 at com.zerog.ia.installer.util.magicfolders.JavaHomeMF.b(Unknown Source)
 at com.zerog.ia.installer.util.magicfolders.MagicFolder.initializeAllMagicFolderPaths(Unknown Source)
 at com.zerog.ia.installer.Main.d(Unknown Source)
 at com.zerog.ia.installer.Main.c(Unknown Source)
 at com.zerog.ia.installer.Main.main(Unknown Source)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at com.zerog.lax.LAX.launch(Unknown Source)
 at com.zerog.lax.LAX.main(Unknown Source)

The application that blew up was the Sony Ericsson Update Service installer 2.2.11b. And guess what: it craps only on x64, not on my trusty 32-bit XP. I pretty much suspect that the programmer of this application didn't expect Program Files (x86) as a directory name.