BBCode bug : Code tag spacing out

For some reason, the BBCode tag CODE forces spaces to come in pairs, playing havoc with the content.

In the following example, the number of spaces incrementally increases ( (2), (3), (4), (5) ), yet the BBCode tag always truncates spaces to an even number.

Code:

Abc  123 (2)
Abcd  123 (2)
Abc  123 (3)
Abcd  123 (3)

Abc    123 (4)
Abcd    123 (4)
Abc    123 (5)
Abcd    123 (5)