Prior to upgrading one of the computers to SP2, you could connect.
This behavior will occur if the IrDA connection speed on both computers is set to 19.2 kbps, or slower.
To workaround this issue, configure both computers to connect at 38.4 kbps, or faster:
1. Start / Run / Irprops.cpl / OK.
2. Select the Hardware tab.
3. Select the Infrared Device in the Devices table.
4. Press the Properties button.
5. Depending on the IrDA model, select the Advanced, Settings, or similar tab.
6. Select Maximum Connection Rate, or Speed Limit, or similar in the Properties list.
7. In the Values, select the connection speed.
8. Press OK and OK.