just take a look in the WL program folder, there you should find the "lame_enc.dll";
you can also replace it with the latest lame encoder version; choose the smaller "non debugging" version for download and replacing; backup the original DLL to not hindering official WL updates;
anyway, take a look in your PM, if you want to get the official WaveLab update;
Greetings from
Duracell