A problem with recording conversion

The way I record myself is via a camrecorder with a mic. I've captured the files via Adobe Premiere 6.5, exported the timeline in *.wav, got rid of noise in Nero WaveEditor and saved in *.mp3PRO.
BUT: after saving in the mp3 format, either there was no sound at all and the graph was still visible (yes, I have checked for sudden sound settings disorder etc.), or there was this weird sound like some alarm going off throughout the recording, varying with dynamics.
The tool(s) I've used to get rid of the terrible noise the camera/mic is taking in: De-Esser for regular white noise, extra Equalizer for a weird beeping sound in very very high frequencies - over 22 000 (must've been a malfunctioning fluorescent lamp) - I've tuned everything over 21 000 down by 99%. While working in *.wav, the sound quality audibly improved with both edits and the high-frequency beeping did indeed disappear. The problem came after the conversion to *.mp3PRO.

Edit: The alarm problem persists also when I manually make Nero save the damn thing as regular *.mp3. I think it might have something to do with the volume of the recording. Not sure. Will experiment further. Will try downloading another program to convert it.

Edit no. 2: Partial victory! It was really the converting algorithm. The Nero version probably has some bug written in it. I downloaded the trial version of Blaze media converter and it converted the edited *.wav without problems.

Thoughts? That's duel recordings I'm talking about! Cry