32MB 5500s do exist; I have one but I've not seen any documentation here that mentions them, they're all supposed to be 64MB.
I thought this was explained to you in another thread - the Sharp ROM splits the 64MB of RAM into 32MB for use in running things, and a 32MB RAM-disk.
If you flash a 64-0 kernel image you will get the full 64MB for running programs.
On the other hand the 5000D has a grand total of 32MB of RAM (split into 16MB for running & a 16MB RAM-disk), so if you've got one of these you're stuck (though you can still flash OpenZaurus, just make sure the two numbers in the kernel add up to 32 rather than 64).
I just saw the fix for the 2.4.18 kernel for collie (Zaurus 5000/5500) into 3.5.3 so I downloaded it and flashed my 5500. Everything works fine until I boot up and it just sits there on "updating modules" for 15 minutes. I thought I did something wrong so I downloaded the older version of the kernel (the one with problems on resuming and suspending, especially the right-arrow button) and it worked fine after I booted up.
I'm sure some debugging would be appreciated.