Hi there Seedar. Don't know if I can help you or not here. If it's you're having trouble getting radio-split-screen, I just went down stairs and performed the procedures on the article mentioned, and it went on with no trouble at all. You might want to try out with starting at V25 downgrade to V24 then back to V25. Cause this is the way that I got the split screen to work

During the downgrade to V24, I turned the radio off at the start and went on with with downgrade procedure(normal software upgrade procedure). After software update is completed, I put the NAV-disc back in then click OK on the screen. It is now, that I turn the radio back on. Then, turned it off when menu re-appear, and turn it back on again. Now you should be able to see split-screen.

After V24, I got my split screen working and upgrade back up to V25 again. Results are great, now I can actually read NAV-information when I listening to radio. Hope this helps