iWork DVD not loading

After updating my minimac to Snow Leopard, I tried tom install iWork ( bought from apple store with snow leopard) but the iWork DVD will not load or spin. It ejects automatically after about 30 secs, the drive will load CDS cds and the snow leopard DVD will load if i insert it, the Iwork DVD will load on my other mac so what it happening please. I am running Mac os 10.6.8