advice/help: audio latency (not MIDI) in Max 6 but not Max 7

Dear forum,

I have a major latency problem with Max 6 audio. Here's an example of the situation:

- trigger any audio change (ie, send an int to [cycle~] to change its frequency) and the audible change doesn't happen for ~500ms.
- this problem is the same for ANYTHING to do with any audio changes.
- Visually, everything is working fine, switch on a sound (for example: opening a [gate~] or similar with the output plugged into a [meter~], the visual response of the [meter~] is instant). It's just the sound that is delayed...

ANY simple MSP patch, any settings in Audio Status, using sound card (MOTU 828x) OR "Built-in Output" audio (OSX 10.7.5) delivers the same delayed audio behaviour.

I've used audio in Max 6 previously without this problem and I don't have any way of pinpointing when this behaviour started because it's been like it for many months (maybe even more than a year). I use Max 6 for MIDI pretty much daily (interfacing with hardware etc) and have no problems at all with latency, it is lightning fast with no discernible latency at all. Whenever I've wanted to run my audio based patches, or do any audio stuff since this problem started, I've just used Max 7 because it doesn't have this problem. But for some reason, right now, I've thought to try and get to the bottom of it and ask for help.

I've tried uninstalling and reinstalling Max 6.

Has anyone else had a similar problem or know how to fix it? What may be causing it? etc.

Thank you for your help!

Joe