Regarding the "glue" - they put a silicone-type sealant over solder joints that have potential to be strained to protect the joint, also on some plugs and sockets for the same reason. Some people have reported cold-soldered joints on occasion in the early aircraft but I haven't seen any similar comments recently so it seems it was an early QC issue... A bad joint wouldn't explain erratic flying or sudden descents, etc, though. Have you calibrated your compass in a good, open area? Have you tried doing an advanced IMU calibration?