First, I have 1.5. I ran Wab Version Changer to trick it to 2.0 (for get some games working)
Now, I want to upgrade to 2.6 (RSS,Webbrowser

), so can I
1) upgrade straight-away or
2) do I need to revert to original 1.5 using WAB version changer before I upgrade?
The reason I asked is that WAB actually flashed the ROM to trick it, so my PSP is not virgin anymore....afraid cant be upgraded officially....
*i am aware of no homebrew after the upgrade*
please help...