Well let me tell you something, several years ago i used the same keyboard with a treo 680 and I can tell you that was awesome, fast typing and by fast I mean very fast, like a normal usb keyboard.
And now... I have a treo 755p and I tought, mmmm I have this keyboard and a Palm OS device again, but when I installed the software from the Targus Page (version 1.35) it's horrible, like a word for 3 or 4 secs

very disappointing, I can't write anything, it's imposible.
Later I tried the driver form the CD, 1.28 EN, that version is the one that i used with the 680, but guess what?? Ohhh no the same thing, horribly slow!!!!
I can't understand it, why with the 680 was a charm, and with the 775p is a lame thing...
Ideas??