Cant get a game to boot

I recently burned the game Urusei Yatsura for Sega CD, I cannot get the game to work in GENS though. It detects the game because it lists it in the titlebar, but if I press start on the Japanese Mega CD screen, it just goes to the CD player. Help anyone?

Edit: Ok, nevermind, found out how, but now I have something else to ask. Is there any way to get rid of the green and red bars that gens puts on the bottom left of the screen?
Errr, I dont know if this applies but I really want to encode the intro, I like it. Any ideas on how I can capture the video and sound output from Gens into an AVI file?
Okayyyyyyyyy, now it seems that I cant get OTHER games to boot, at least not directly from the iso in Gens. Do I need the mp3s/wavs and a cue to make the game work? Because unlike UY, the CDROM button when the Mega CD boots is missing when I try these three other games.
Hmm............. its on autoselect, and I dont really know what country the games are. And I know this one game worked before, but its not working now. I dont remember if I included the mp3s back then though.