"Define bugs..."
Roger,
You are assuming that a bug is only caused by the code itself, but you should also take external influences in consideration.
consider the following :

while (1) {
	read (<complex datatype from network packet> )
	subroutine(data)
}

something different : what if the code is run on another architecture?
As we do not know the way future hardware-architectures are going to be implemented, the code could give new bugs. This way it is definitely infinite.
(the example above probably is finite)

There's also the point of bugs being solved and creating new bugs.

Something to think about : when you believe the universe is infinite large, you can never find the smallest particle, as it will also be infinitely small

Frank van Gestel