Need help on choosing the correct firmware for W890i.

I want to try flash my w890i. which files should i download ...R1EA020_RED52 ? R1EA030_RED52 ? or all five R1E******* of them? And then which is for my phone whether fs APAC, GENERIC, TAIWAN? How do i rectify it?

I bought the phone in mid-year 2009 and never update or change anything regarding these flash things.. Please guide me...TQ

Ok..sorry for this repetitive Q&A, i've checked my phone and its R1EA033_RED52 but from where should i search to know either FS_C-ASIA_RED52 or TAIWAN..?? I bought the phone in Malaysia..

What language use?

All in english.