Arwin has released a new version of Basilisk with improvements made by him, heres what he says:
"Anyway, I fixed a few small bugs. Now that there are two input routines dealing with either extended mouse control or the p-sprint integration, the 'Enter' key should be left to p-sprint. It's not necessary, but there's a small key-repeat bug (the Enter key now 'sticks' in keyboard emu mode) that you can simply get rid of by removing the non-p-sprint handling of that key. I also fixed the (number) 9 key (now gave 7) and the 5 and 6 keys (which were reversed). Other than that, most things seem ok now. You can test quite well with the Key Caps application - holding the key will eventually light it up on this virtual keyboard.
I also think that the extra mousemode isn't really necessary if you work out the threshhold levels better - only put full mouse speed near the extremes of the analog stick range, and let everything in between be slow/precise movement that you have on the cursor keys now should do the trick and removes the need for switching between different methods. I'll have a look if I can at least modify the p-sprint routine to work that way, then it won't do harm either "