this is what happened to me.
i lost 4pts in 2004 (double demerits) for neg driving.
in 2006 (in the space of JUST over a month), i lost 3pts for speeding, then another 3pts for speeding, then 8pts (double demerit) for doing 30 over, then 3pts for speeding.
at the 8pt fine, i'm well over the 12 demerit points (18pts). a month after my 8pt fine, i had paid for 2 fines first - 4pts(this was paid ages ago), 3pts, 8pts - total of 15 demerit points then I paid the remaining 2 a couple days later. I then recieved the letter from the RTA saying i had a total of 15 demerit points (even tho by this time ALL fines were paid for). This means they only counted the fines that i paid for first which pushed me over 12 demerits points not the ones that came after.
so after 6 months, i got my license back, and i have 6 demerit points.
To the person that asked about getting busted 45 over with 1pt remaining on ur license - from my experience, u won't get the extra points added on to ur license when u get it back if it's just one fine.