jquery autocomplete restricted max items to ard 300 but it works in ie and others, any solution?

Question

var tags ="s1,s2,...,s1670";

$("#newtag0").autocomplete(tags, {
      minChars: 0,
      width: 310,
      selectFirst: true,
      multiple: true,
      cacheLength:1672,
      max:1672
});

This will work in IE 7 and 8, chrome and safari but in firefox it results only s388 last with no errors.. Means 4096 chars..

Is it browser restriction, need to figure it out..