The site is http://byo.com/
It is Joomla 2.5.9. Virtuemart 2.0.18a PHP Version 5.3.18. This was just converted from Joomla 1.5 and Virtuemart 1.1.8.
Every once in a while it will skip 1 or more order numbers. It does't happen with any pattern or frequency and has happened 3 different times in one week. I saw a similar error in the VM 1 forum and it looked like it might have been related to software versions. All our software is up to date. Hoping someone would have some ideas of the cause or if anyone else is experiencing this issue.
Thank you,
Heidi