Hi Buzzangie, Its good to see another member of the byetta community on here. You will find there are quite a number of triggers that can cause nausea while on byetta, including too long a time interval between injecting and eating, and eating very greasy or spicy foods, as well as just overeating. Most users seem to find that any nausea symptoms they do have wear off once the body acclimatises itself to the medication - generally a week to 10 days but can be longer as in Silvercat's case. I was very lucky - I experienced just slight queasiness for the first 3 days on the 5mcg dose, and the same when moving up to the 10 dose.
Let us know how you get on.