serial rs232 adapter belkin keyspan

Hi Folks!
A while ago I bought a Keyspan serial adapter for the Mac. I
just bought a Toshiba Laptop (no serial port either) so I went back to
CompUSA for another adapter. I didn't see any more Keyspans, but they
did have just one Belkin F5U409. One program worked with it, all the
others locked the computer solid. I had to hang on the power switch
to shut it off.
I uninstalled those drivers, and put the Keyspan on the laptop.
Now all the programs work.
Funny, there is no software updates for the Belkin on their website.
I search for F5U409, and it points me to the 109 drivers. Maybe these
would work, but I'm not willing to experiment.
Stick with Keyspan folks.
Take Care!
Harry