That whole "rich" text editing thing did me decide to go for a wireshark trace. Sure enough every 20 seconds a POST is passed onto the server which contains all the characters typed in the editing field so far. I noticed that missing characters always coincide with a POST message, although not every POST causes characters to get lost, only some do. I assume it must be some timing issue where VUgen tries to parse the character to the browser and at that same time the browser sends a POST to the server.
Anyway, I am convinced now that VUgen is not the cause, although I do wonder if there isn't some setting in VUgen that might cope with this effect...
Thanks for thinking along with me people!
Regards,
Peet