I can't get avrdude 6.1 dated March 13 2014 to work with com ports. Neither real ports nor virtual ports. It does work well using flip2.
avrdude 5.2 works okay with com ports but it doesn't have flip.
I have attached the avrdude 6.1 failure log using -v. It starts and ends correctly except for the verification failure. However between the start and end there are over 7300 lines that just say "***failed;"