There are currently two modems that support shaws Internet 150 - the Hitron CGNM-2250 and the Cisco DPC3848-V.
They both contain the faulty Puma 6 chipset which, in case people do not know, is a fault in the modem causing frequent disconnects due to a flood of packets.
This MAY be causing your connectivity issues, it is affecting mine.
There does not seem to be any fix available.
Now, how is this fair? I'm so sick of internet drops every 5 minutes. As an easy fix, Shaw should provide more modems that do not contain the faulty chipset and that can handle the 150 speed. This has been going on for too long.