generally this problem occurs if your phone's original layout is corrupted.so may upload original layout on your SE W810i to: tpa\system\layout
the same problem happens when i applied patch to my w550i(old phone too). i solved my problem by flash my phone using setool2lite on Windows 7.
i've not yet faced any problem on Windows 7 which i did on Windows XP. so i don't think you need to setup Windows XP to flash your SE W810i.






