I recently had what they call a "prolapse" which as far as I can tell is a minor slip. You will definitely know when you have had a slip.
Last january (about 4 months after being banded) I went to the ER being unable to keep Water down. They said I had acid reflux and to eat better foods.
About three weeks ago I went to my aftercare facility with similar symptoms to last january. I did a barium swallow and my stomach had somewhat mushroomed over the band, when its is supposed to look like a banana coming out of the band connecting to your esophagus. They took all the Fluid out (but I am still having problems, which may be related to a current ear infection as mucus and nasal drainage can cause blocking in the lap band).
Until you are having constant heartburn and/or unable to keep simple foods down (i.e. pudding, Soup, water), don't worry.
Try to eat slower and don't drink through straws. before even being banded, I would get the hiccups when I ate too fast.
Hope this helps.