An Air Carrier on a visual approach to IDA was issued a go-around when overtaking a previous light aircraft on a practice instrument approach. The reporter listed improved and more timely communications as preventative measures for future same type events.

Narrative

While attempting a visual approach to Runway 02 in IDA; SLC Center cleared us for the visual approach and switched our flight to the Tower at approximately eight miles from the airport. A GA aircraft was cleared to land prior to our flight and we were cleared to land at approximately five miles. The GA aircraft was touching down as we were at approximately two miles. At about 1/2 mile; the Tower instructed us to discontinue our approach and go around to the right. As we executed a go-around; the GA aircraft began a go-around maneuver at the same time. During the go-around execution; the IDA Tower Controller requested we switch frequency to SLC Center Control. Maintaining visual separation on the GA traffic at all times during the go-around; we checked in with SLC Center and explained we still had IDA in sight and requested to be sequenced for another visual approach. He gave us instructions to turn to a 200 degree heading (downwind) and we complied as requested. As we approached the abeam position; he cleared us for the visual approach again. During the downwind; we noticed another aircraft 1;000 FT below our altitude and heading directly toward IDA within three miles of our position. Had we complied and initiated a visual approach; it would have caused an aircraft separation conflict. Therefore; we maintained our heading and altitude until we could gain clarification of this inbound aircraft's intended plan. As it turned out; the inbound GA aircraft was conducting a practice instrument approach to the same runway we were cleared for our visual approach. Once the aircraft cleared the area and a safe visual approach could be conducted; we executed an uneventful approach to landing on Runway 02. On the ground; we queried the IDA Tower Controller as to the previous event. The Controller indicated that it was going to be reviewed.[I am] unsure as to why there was so much confusion in what should have been an easy 'no-brainer' approach and landing in IDA. Weather was CAVU and there were only the three aircraft described in the area.The only thing we could have done differently would be to have prompted SLC Center to give us an earlier handoff to IDA Tower. At that point; when it looked like the interval between our aircraft and the GA on short final was not going to work; we should have asked for the intentions of that GA aircraft and the plan for our aircraft. However; that seemed to be micro-managing a situation we should not have been required to oversee.