Speex dev - May 2010 - Can't seem to turn off VAD

Hi there,

I'm having a problem turning VAD off in Speex. I'm using version
1.2rc1, and I'm passing --disable-vbr at configure-time, which
`configure --help` says should also disable VAD.

I'm testing with a 1 kHz tone from a test set at either 0 or -10 dBm.
Before I disabled VBR at configure-time, both tones would become very
distorted after a couple of seconds, but become clear when the tone's
frequency was changed. After disabling VBR, VAD still comes on at both
levels, but it can take a while (1-2 minutes is typical) to come on at
0 dBm. As before, the tone becomes clear again when the frequency is
toggled.

Any ideas? Is this VAD kicking in, or is there something else that
might be going on?

Thanks for any help anyone can give,

John G