ISI Hybrid ISDN card has poor throughput with internal Eicon DIVA card.

Using two TA ports of the ISI Hybrid card with Windows performing MultiLink PPP to dial out to an internal Eicon DIVA ISDN card results in a file transfer with poor throughput in the 86kbps range. Throughput should be greater than 120kbps. Updating to the latest Eicon DIVA drivers fixes the problem.