Write a better version, then steal their business. Oh, and demand a refund cause their code stinks.

I agree with Jaap - tell your boss that you can write something better in 3 months, which would be the amount of time you'd take to speed it up and deal with the first upgrade. Heck, you could upgrade it, then sell your upgrades back to them!

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.