I have been trying to make FLDigi work on my K3, finally it does... I searched for all the cygwin1.dll files and deleted them, then searched the hard drive for any fldigi remnants, found a few and deleted them. Deleted the fldigi I had extracted, and extracted a new fldigi3.01. Put in RTS and Com 4 and it works perfectly. Obviously bits from a previous fldigi had "been hanging about" preventing the program working correctly.
Congratulations and thanks to Dave W1HKJ for all his hard work, now for the fun of using the program. Regards to all Ross ZL1WN