Flex 6300, Windows 10 Pro 64-bit, 8 GB RAM, AMD Athlon X4 860K Quad Core Processor, 3.70 GHz. After installing SSDR 1.5.1 several weeks ago, I have randomly, but too frequently, encountered a severe latency in frequency tuning with the Flexcontrol installed on physical COM6 when tuning in cw contests. Virtual serial port pairs 4-14, 5-15 defined. Running fully integrated N1MM Plus on COM4. When I attempt to tune, frequency will freeze and stay hung for 2-3 seconds, then resume tuning okay. I never experienced this on SSDR 1.50 and earlier.