Latest experimental version... Rated 4 out of 5 stars
It does call out Lingvo 11 for translating a word, so I noticed no bugs in the add-on itself.
But when you occasionaly give Lingvo several words, it falls on Word-by-Word translation (it's incompatibility of Lingvo 11 with Limited user on XP, I suppose).
I would be glad, if you used not the programm Lingvo, but its dictionaries for your own translating engine, so that people wouldn't depend on bugs in Lingvo. Nowadays people must either have an Internet connection or Lingvo to use your add-on. And if they choose local Lingvo, they can call it out without help of your add-on just by Ctrl-C-C or Ctrl-Ins-Ins.