WORKING on WIN 7 64 BIT!
Hopefully, this will save someone a lot of time and frustration.
The drivers supplied by Kawa with the CAT cable sold on ebay did not work on Win 7, 64 bit on my new HP e9240f machine. I downloaded a new bunch of drivers in the 3.3 series that also did not work. Kawa responded to my email with a new (older set) that also did not work.
But extensive searching on the web got me to a "Greenwire IT" site where someone had posted a pointer to http://www.usglobalsat.com/download/546/win_drivers.zip
These are drivers for the Prolific 2303 chip (in the CAT cable) meant for a GPS. They downloaded and loaded perfectly, and soon the CAT cable was recognized by the PC without error codes. It still would not recognize the FT 897 in HRD (version 5 beta build 2434). I set it to Com 3 (used by the CAT cable) and it started to partially work, but showed errors. Dropping the speed to 4800 solved the rest. I did not need to set the RTS, CTS etc.
All in all many hours, but all ended ok. We need to pound on Prolific to supply up to date drivers for Win 7, 64 bit on their site.