Can i upgrade to ..IA5 rom ?

[Guest Adriafix]

Since i am new to omnia, can someone explain the reason why i can`t upgrade and downgrade my device as i wish like i do with my htc p3600?

where can i find more informations about this?

Right now, i´m using a portuguese rom DXIA2, can i upgrade my device to ..IA5, or do i have to install another rom first?

And if i don´t like it, can i downgrade to DXIA2 again?

Thanks for your help