I thought of that at first, but seeing as they are both in great condition (the one with perfect lettering bearing more marks than the other) I don't see how this would be. Further examining of both coins I can see that the curving (image 2) has "ELIZABETH II D G R (of REG)" being effected with "EG (of REG)" not effected then "F D" effected, and the date with no effect. The obverse being unneffected on both coins. Looking at other dates (from the few that I have here) I have one curved 2003, two curved 2002, and one perfect 2001. Silly suggestion(?): Could it be that the mint changed the lettering design in 2002, but then decided to change it back to how it was after some 2004 pennies had been minted? The only 2005 penny I could find has perfect lettering. Edit: Just looked some more, the 1998, 99 and 00 pennies I have also have perfect lettering.