Recording issue (more than likely a newbie issue)

I'm completely new to AA and I've been having a recording issue since I installed the program. When I begin to record, the volume of the track stays at the proper level...but as I continue to record it slowly dips, only to climb back up to the proper level again. When I play the recorded track back it sounds like some sort of flange effect or something is on it, but I don't have any effects on. The track will just not stay at the same volume from start to finish.

Any help would be appreciated.

Thanks

It doesn't sound like a newbie issue to me at first reading!
I need some information first, just the basic facts, can you tell me .......(apologies to Pink Floyd fans)

How are you recording - in Edit or MT mode?
What machine do you have and what soundcard?
How is the signal getting to your PC?
From what instrument?
Can you post a sample?
Haveyou tried closing AA and starting a new session?[/list:u]

With a bit of info we may be able to help!

Thanks for the speedy reply  

1. I'm recording in MT mode

2. Compaq Presario 6015CA
    AMD Athlon XP 1800+ @ 1.5ghz
    512MB RAM
    ATI Radeon 9800 Pro 128MB GPU
    60GB HD1
    5GB   HD2
    Mainboard - Compaq 07D0h - nVidia nForce AGP controller (which
    means I use onboard sound --> SoundMAX Integrated Digital Audio
     
    Windows XP Professional -SP2

3.  The signal is running to the mic port via a normal guitar cable
     locked into an audio adapter fitting.

4.  I am recording with an electric guitar plugged into a distortion pedal
    (tried not using the pedal...still happens) -from the pedal straight into
    the mic port. I also use an acoustic guitar with an attached mic
    -leading directly to the mic port.

5.  I have tried closing AA as well as starting a new session...didn't fix
     anything.

My guess would be that AGC (automatic gain control) is enabled on the mic input.  Open the windows mixer and see if you can turn it off.  You might try using the line input.  It's a mono signal so you'll want to select the left or right channel (whichever one has the signal on it) when recording.

You would do well to get a mixer to put in the middle of this - it will give you a lot more control over things - and if you get serious about this recording thing you'll want to get a better sound card too.