unwanted clicking

[Setherial]

firstly, i have cooledit 2000...and tech support has'nt been able to help me. i get a loud click at the end of a recording which remains even after using the evelope option and or snipping off the end...which renders any recording useless! now, this does'nt always happen...mostly when i use the generate tones or noise option...but i never know when that pop at the end is going to manifest...help!!