Finally,customizing and changing the XMB icons on 3.30 OE-A is possible,but it won't work if you copy a topmenu_plugin.rco made for 3.03 OE-X,so you need to convert it in order for it to work under 3.30 OE-A:
First of all,download this pack,it contains all the needed files:
extract the pack you just downloaded,you will have this:
Ombres: small .bmp pictures used for creating the topmenu_plugin.rco creation.
RCOEdit113b: that's the program we gonna use,don't worry,no virus.
topmenu 3.30: this folder contains the clean 3.30s topmenu_plugin.rco.
Creating the topmenu_plugin.rco for 3.30 OE-A:
1)open RCOEdit,then click "Open RCO" and select your topmenu_plugin.rco that used to work on 3.03 OE-C,search the forums they are many good one.
2)Once the topmenu_plugin.rco opened,click "Extract All",choose your destination folder,in our case it will be named "new folder" simply,wait for the extraction to finish.
3)Now,extract the "ombres" rar in the "new folder",winrar should ask you about already existed files,remplace all.
4)Go back to RCOEdit and click "Open RCO" again,this time open the 3.30 topmenu_plugin.rco located on the "topmenu 3.30" with the pack you just downloaded.
5)Once the topmenu_plugin.rco opened,click "Replace Multiple" and choose the "new folder" we used before.wait for it to complete.
NOTE: if you get an "Subscript out of Range" error,go back to the "new folder"
and delete all files: tex_transparent.dat , tex_transparent.mig, tex_transparent.8bit.bmp and tex_transparent.32bit.bmp .
Your new topmenu_plugin.rco is now customized,and ready for being flashed on your 3.30 OE-A.
Flashing topmenu_plugin.rco on your 3.30 OE-A PSP:
1)Open recovery mod by holding R trigger when booting your PSP.
2)Pick Advanced on the recovery.
3)choose the option Toggle USB (flash0).
4)Connect your PSP to your PC via USB.
5)Your flash0 will become as an amovible disk on your PC.
6)Copy your new created topmenu_plugin.rco in vsh/resource.
NOTE:do NOT touch anything else on the flash on your PSP or you will screw up your PSP,also watch out for the flash0 memory available.
Tested and Confirmed Working