Translating between int and float creates noise because rounding errors are introduced during the storage format conversion. Try reading a 2G file into audacity and then writing it out to another file name. You will rarely get an exact duplicate.
Bingo! [snip]
Okay, I think I get this now - in the process of simply reading and then re-writing a 24-bit WAV file, with no editing, Audacity is not bit-transparent since it (behind the scenes) converts the 24-bit file to 32-bits and then back again to 24.
This all got me curious, so I just installed and fired up Audacity 1.2.4 on Windows 2000 SP4. FWIW, after changing the output format to 24-bit (from the default of 32bf), opening a 24-bit file in Audacity and exporting (saving) to 24-bit WAV has proven bit-transparent every time I've done it (about half a dozen, so far). I wonder if the latest version has solved the problems you've experienced, FL, or if something fundamentally different is happening behind the scenes in the Win version v. the Linux version.
At any rate, FL, sounds like you've banged your head against that wall plenty in the past, and I don't blame you for bailing - I, too, would much rather record and listen than dork around with computer config stuff constantly!