Corrupted files

[MikeSym]

Hi, first time posting here so wasn't really sure as to where the best spot would be for such a post but since i have the 700wx figured This would be as good a place as any. After putting some Mp3 files on my SD card my phone seemed to be acting fine. I saved a few of the songs to the phone using the sound manager so i could set them as ring tones. However, later that night it frooze. I did a soft reset but to no avail and tried removing the battery several times. After going to Verizon they told me that most likly i had saved a corrupted file. I was forced to get a new phone which i have now. However after this incident I am slightly nervous to put any more music files onto my phone. Is there anyway to check the files for corruption before I do so? Or should i be putting them on my phone in wma format and if so how should i go about changing them from mp3 format to wma? Thx.