I've had this pack of Verbatim CD-R's for about a year now and PS1 games I burnt onto them longer ago (at 8x write speed) like King's Field and Klonoa still work fine. For more recent games I've tried like MGS and Tail Concerto though, the discs just stop spinning and my console goes to the menu as if it doesn't recognise the format. Could the discs have degraded? They've been safe inside their plastic cover this whole time.