Which PIC are you using? The recent dsPICs have some problems with EEPROM. I think this may not be the case for you but you can still check the errata. Eg: From dsPIC30F4011/4012 errata (can not copy/paste from datasheet?!?!) "The most significant bit of every fourth byte in data EEPROM may be corrupted on any write operation. This write corruption may occur while using either ProMate, MPLAB ICD2 or Run-Time Self-Programming (RTSP)" Regards, Xiaofan -----Original Message----- From: PicDude [mailto:picdude2@narwani.org] Sent: Thursday, September 08, 2005 3:44 PM To: piclist@mit.edu Subject: [PIC] Speaking of EEPROM... Had a problem recently where the EEPROM data on a PIC got corrupted during operation. I feel strongly that a power-surge/issue caused this. Is this really possible? Or are there other conditions that can cause this? Cheers, -Neil. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist