cubase sx midi problem - 'hanging note'

[rigamortis]

i'm using cubase sx with a roland v-synth (external hardware) midi'd up.

if i record say a c, then stop recording, the c note continues to play, even if i shut cubase down completely.

it's not the release on the v-synth, i haven't changed anything inside of cubase recently, and then the only way to shut the synth up is to kind of overload the maximum polyphony by pressing as many keys as possible on it.

it only does this with notes that i've recorded, though, keys that have been pressed during the recording.

if i then press any of the notes on the keyboard that i've used to record in the sequence, it has a kind of infinite release on it.

WTF?

anyone else ever had this?

until i get this sorted i'm screwed.