Do not play that disc! If you have the Holiday 2004 Demo Disc for the Playstation 2, you should take notice to this warning that is being put out by the folks over at Capcom:

If you have received a copy of the Holiday 2004 Demo Disc including the playable Viewtiful Joe 2 - please take note.

It has just been brought to our attention that there is a glitch in this demo which will erase all of your saved files from your Memory Card(s). If you have not yet played the Viewtiful Joe 2 demo, please remove your Memory Card(s) from your PlayStation(R) 2 computer entertainment system before you load the Holiday 2004 Demo Disc.

Sony Computer Entertainment America would like to express our sincerest apologies for any inconvenience this may have caused you.

No word yet on if they plan on sending out replacement discs or not just yet. If you know anybody who might have one of these though, please spread the word!