I didn't know about this DVD until today. While I was flipping through channels I saw an interview with Andrea Corr.. I kept watching, Sinead came on, then the "From Limerick's ashes" part came on with some nice Cranberries footage.
Litsa, if you can't find it anywhere, you can overpay and get it through the channel that aired the show:
http://www.wliw.org/productions/performance/music-of-ireland/637/ It's a "donation" for the public channel and they give you the dvd as a "thank you"
