Since I installed the latest upgrade, My down imaging (DI) screen shows some type of interference. Side imaging and 2D sonar work fine, but the down imaging screen is solid interference. If I change from some other view to down imaging, it show the recent past fine, but instantly after switching to DI view, the screen clutters? I took a snap shot this weekend, but haven't removed the SD card to put upload it to my PC. My unit is set up to be portable and can be used on a trolling motor or transom mounted. I have not used the unit on a trolling motor since I installed the update but have used it on two different boats and DI screen did the same on both. Any ideas. Thanks.