Ok, if the Autothrust is active it will attempt to increase speed so as to maintain Vls, if the speedbrake is also deployed the SPEEDBRAKE display on the EWD will flash amber as it senses a power against speedbrake condition. (this indication will not occur on early FMS A320's).
If the Autothrust is off, then the speedbrake will automatically retract when the AoA reachs AFLOOR, (as it will eventually do with in your scenario) and all the protections will try to fly you back to VLS.
I think the scenario you refer to is when selected (or managed) speed is slow, say green dot, but you are a bit high, so use the speedbrake which raises the vls so that it is just under your selected speed, you then turn and the aerodynamic increase in stall speed sends your amber vls tape over the top of your selected speed. Autoth will try to increase your speed and the amber speedbrake caution will come on.
In real life this scenario is quite easily reached if you ask the aircraft to do too many things at once, for instance, asking it to accelerate, climb and turn at the same time when at high weights and slow speed after take off, small buses don;t have vast surpluses of energy to cope and the FMGC will prioritse what you ask of it to its own logic. It will sort itself eventually. Hope this helps.
Last edited by macdo; 10th June 2012 at 08:38.