BufferTokenStream returning wrong input data.

[vikrambose86]

var lexer = new NCalcLexer(new ANTLRStringStream("GET([Area].Area)"));
var input = new BufferedTokenStream(lexer);

Input : GET([Area].Area)

Old - ANTLR3.Runtime - 3.3.0.7239
output from BufferedTokenStream: GET([Area]Area)
Exception message is : extraneous input 'Area' expecting ')'

new - ANTLR3.Runtime 3.5.1
output from BufferedTokenStream: GET([Area]rea)
Exception message is : extraneous input 'rea' expecting ')'

Why these differences in old and new version?