my backups used to work and now they dont.Why?

Hi Im am new to the board but I hope someone out there can help me.I recently bought a DC and acquired some backup games.My kids are a bit heavy handed with the cd's and I was worried they would get damaged and stop working,so I used CloneCd to backup the backups!They worked fine at first but now the self booting ones wont work,although the ones that require a bootdisk still work,and even if I make new backups using the same method as before,they wont work.However they will work if I give the top of the DC a bit of a thump as its booting them up.Obviously I dont want to have to do that everytime I want to play for obvious reasons.The "original" backups still work fine!Has this happened to anyone else? And if so,is there a way to fix it without having to whack the DC each and every time.Cheers,Bob.

sorry to bump my own post but I really need some help

[knuckles]

Well, I don't know if this is the prob, but if you copy self booters with Clone CD then you will find that they tend to take longer to load up (about 20 secs) than the first copies.