As you ahve already know, mxcl has a problem with G4. Unfortunately, G4 friendly eversion of mxcl is not available as a download(I maybe be wrong... in few hours... hoping that they will post a new version or post separate binary soon ). You might need to contact NL for this.
After reading about the new mxcl file here, I sent Miguel Talens, at NL, an email for it. Try emailing Miquel, if NL doesn't post the file. I received the mxcl the next day, however, it arrived with a permissions glitch. See the thread, Mac G4/M~R Alpha 1.033 fix, for more info on the permissions fix.
It is very strange that NL has not posted the file or offered a reason for not uploading it. Have you tried Victor <victor@nextlimit.com>? I will also send Miguel and Victor an email to request that they post the mxcl file. If you don't hear from Victor, send me a personal message.