When they talk about slippage, they don't mean that the band itself slips......it is the lower stomach that slips up thru the band into the pouch. The older bands had some problems with slippages, but the new ones (like you probably have) are doing much better.
Slippage is usually caused by vomiting....not just sliming, but real vomiting - that's why we have to be so careful about eating small bites, chewing well, avoiding stuck episodes as much as we can. However, just because you get stuck doesn't mean you are going to have a slippage, so don't get paranoid about it.
And even if you do get a slippage, very often they can empty your band, put you on liquids for a few weeks, then the stomach tissue slips back down where it belongs....you begin to get fills again and start all over.
I've had two slippages and am now scheduled to have a 'new and improved' band put in soon. I'm ready!!