I'm using Photo Mechanic 4.6.7 on a Windows 7 Machine, Intel Core i7 870, 8Gb RAM.
I have a Calumet Firewire 800 card reader with a FW400 adapter going into the motherboard's built-in FW400 port.
When I ingest from this reader with PM, ingest will stall, sometimes for 5-10 minutes, sometimes multiple times during one ingest. Sometimes, it will freeze completely and I have quit out of PM using End Task.
Using Explorer, I can copy cards from the reader to the hard drive just fine.
The machine also has a built-in reader and PM ingests just fine through that.