It sounds a lot like leash reactivity. You'd be amazed by how many dogs actually have it. One of my dogs, Ivy, is/was very leash reactive.

See this thread for ideas on how to retrain a proper greeting/coping skills:
http://petoftheday.com/talk/showthread.php?t=142274

See this link for info on what leash reactivity is and how it isn't necessarily dog-dog-aggression:
http://4pawsu.com/onleashaggression.htm

Many people recommend using 100% eye contact when dealing with reactivity, but I personally like the game of Look At That, instead (LAT is explained in the first link). LAT was coined by Leslie McDevitt in her book Control Unleashed, and I highly recommend you give it a read.

ETA: I also recommend familiarizing one's self with subtle dog body language and movements. If you pay close enough attention, you will see very distinct signs of stress and excitement. These subtle signs are key to helping your dog cope with her stress/excitement.