No dvd in drive

Since i have installed AnyDVD, when i insert a dvd the computer does not recognize it. It doesn’t do it everytime but enough to be aggravating. I have a: Compaq 3400+ amd anthlon 64proc 512mbram and 200gbhd and am running winxp home ed. I use dvd shrink, nero 6 ultra and dvdxcopy platinum. My father is having the same problem. If anyone else has had this problem tell me how to fix it please. thanks