Heyo!
Sorry to hear you lost those bits!
You don't need the drivers for your N900 -- only if you plan on using this keyboard with other devices (palm, symbian?).

I did have to read the manual on the drivers CD to figure out how to put it into pairing mode, but it's simple: hold down:

"Cmd" + "Find" (the "Memo" key in the upper right corner)

then the red light should start blinking to indicate that it's in pairing mode.

What I did to get it working:

1) Paired the keyboard w/ N900 via regular N900 bluetooth settings panel
2) Turned off keyboard
3) Created a .btkeyboard file in my home directory w/ the appropriate entries (pc105, us, etc.) --> the defaults listed in this forum topic
4) Ran HID-Watcher script
5) Turned the keyboard back on, paired it up again
6) After doing this a few times, it started working

I'm not sure I ever got the HID-watcher working correctly... I ran it plenty of times but it didn't necessarily look like it was "doing" anything in particular. I ran through the sequence above a few times w/o (seeming) success, but at a certain point the keyboard starting supporting the special characters, numbers, etc. And now every time I pair it (normally), it continues to work.

hope this helps!

Sam