I was running DP 8.1.1 on my N920 and wasn't about to wait for At&t and MS to get us everything we need to update to Cyan. So I downloaded the firmware update thru Navifirm (RM821_3051.50009.1424.0018_RETAIL_eu_italy_233_18_440723_prd_signed.ffu) product code). Use the product code for the Italy Vodafone. I was then able to download Cyan. I then reactivated DP and got their updates. I never reverted tp WP 8. All my apps were still intact as well as my contacts. It's all working great with more fluidity...better camera work and better battery life.