@Ian *******
I have used Visa exemption/on arrival successfully for the past 8 years without any problems. But I am now retired and have been staying in Thailand far more recently with a view to moving to be with my girlfriend permanently. I think I have been put on notice purely because of the frequency and length of my visits. I think given that you have only been in the country for 50 days you should be OK. I cannot see Immigration refusing you at this stage (don't hold me to that! ) but if you are changing your pattern of stays I would perhaps be a bit cautious.