Latency with external instruments

HI Peeps,

I’m having the following problem with Cubase5.
When I use an external (mono) instrument, I get latency.

For example, when I use my Roland Super Jupiter.
I add a mono channel + Midi channel (through an AMT8 -Emagic)

I play something, and then I put the midi notes in the correct place. (for example all on 16th notes)
I then have latency on playback …if I then compensate the latency on that midi channel everything plays perfect.
However, If I hit the “record” button on the audio channel, then it records the audio with latency again.

Any help on this would be fantastic.

ps: I experience the exact same issue with my: Roland System 100 - 101 + Vermona DRK MK2