DVD Player, Multi-Region Playback (need clarification)

I own a 13" MacBook (Alumium) from late 2008 and recently purchased a Region 2 DVD set from the UK. I'm looking forward to watching it but need clarification on playback. A few months back my girlfriend recieved a Region 2 DVD and before playback it asked what region the DVD was before successfully playing. I have read in other posts that there is a limit of 5 before you have to reinstall the OS.

Can someone please clarify what that exactly means? I would have to have bought this DVD set only to watch it 5 times on my MacBook if that is what it mean.

Thanks.