jecasc - 8:46 am on Jul 13, 2010 (gmt 0)

As for codes not working - we had a similar problem with passwords. People forgot their password and requested a new one, and then claimed the new password did not work. Since this happened at least 3 times a week I made the following changes in the function that created the passwords:

- no I or 1
- no 0 or 0 or o
- every secend letter a vowel

So instead of
xIt0nokrfO1

people now receive passwords like this:
KamiTuneParami

Could be the same problem with your coupon codes. If the contain I10oO this are easily confused.