After a few tries I managed to get Portable OpenOffice to work on a USB memory stick. However, a new issue has come up:
I tried recording a very simple macro, for testing purposes. I selected some text and made it bold in Writer. After saving the macro in a new Library, I tried the command "Run macros...". As soon as I do that, the program immediately exits with no warning or any indication of a problem. I restart the program and it goes into crash recovery, but the macro is nowhere to be found.
I tried recording a macro on another PC where Java 1.42 is installed. At one point just before crashing, the program showed a message stating that "the selected JRE is defective".
The program always crashes when I enter the Tools--> Customize... menu and select the 'OpenOffice.org Macros' in the "Functions" Category. The entry shows a "+" where I'm supposed to open the stored macros. When I click on it the program crashes and exits, or as stated above it shows the message about JRE.
It's worth noting that in the same dialog there is an item 'Styles' with a "+" sign next to it, but it does *not* cause the program to crash when I click on the plus sign to open it.