How long can DNA converted with EpiTect Bisulfite Kits be stored before use in methylation specific PCR with the EpiTect MSP Kit?

We have data for DNA converted with EpiTect Bisulfite Kits showing that the bisulfite treated DNA is stable for 3 years at -20°C before use in methylation specific PCR with the EpiTect MSP Kit, or the EpiTect MethyLight PCR Kit.