I'll bet the fourth character being a "0" is the culprit. Try restricting
yourself to using ONLY LETTERS in the first FOUR characters and ONLY FOUR
sequential NUMBERS in the last four of the name in the future. And, never use
less than FOUR letters. (I know that diaquest requires this exact protocol)
For now, Type "RENAME pic?0*.tga PICZ0*.TGA " to correct your names.