I've used v10 forever and needed to install on a new laptop, and cannot for the life of me find the solution to this problem again! I remember having the problem last time I installed it, but did not save notes for the fix.
This only happens with SQL documents.
When I typed any digit, I got the error: "Procedure needs more arguments"
I played around and fixed it by unloading and reloading the plsql.e module under the Macro menu.
All set! Hopefully this helps someone else, and I will make a note of it for future installs in case I never upgrade VSE.