I am having my band changed to something else because of the same thing. I had my surgery 12/06 and I have been in pain ever since.
I am on my second surgeon he finally gets what I am going through
and is recommending a revision. He removed all my fill for a second time. I have Vanguard band and the most I have ever had in it was 6 cc. The slime you are talking about is the the mucous lining of your esophagus that protects it from stomach acid. I call it a Jellyfish!
Eating has become an ordeal not a change of life style. I never new when it would hit and on what kind of food. Food that was OK to eat one day was bad the next time. Going out to dinner is always scary. I also never really lost any true weight with the band I have now. I could not eat the proper foods. I know your pain!
I am considering a Gastric Sleeve for my revision the doctor also suggested the new band from Johnson & Johnson but I already saw I could have the same symptoms with it.
By the way my wife and I had the surgery the same day with the same kind of band. She has only experienced this type of issues when her band was past 9 cc.
So remember everyone is different and you may need to speak to your doctor about a revision too. At least get someone to look at your esophagus to make sure it is OK.
Regards
gfd406