SWMBO asked me to order a book for her this morning, so being the tightwad that I am, I go hunting for the ISBN and the cheapest place to buy it.
Amazon has it for £17.24 and Waterstone's for £18.49 (but if I order through quidco, then I receive another 8% cashback, making Waterstone's cheaper).

Waterstone's need me to create an account, fair enough and state "Also, please be aware that passwords are case sensitive, and must be a minimum of seven characters long and at least one character must be numeric."  Again, all fairly standard.

So each time I try to enter a password which meets this criteria I'm hit with a javascript popup that claims: "Your new password must be at least 7 characters long and contain at least one digit."

"But it is!", I yell in frustration.

Using the Firefox "Web Developer" plugin I unhide the password boxes and see that my password doesn't have digits... wtf!   I enter the digits again and find there is another hidden rule:

<input name="newPassword" type="password"
id="fPassword" size="40" maxlength="16" value="" />

Yes, an upper limit of 16 characters on the password.

Right ok, make a password of 16 chars or under and move on...

Add name, postcode to the next form and it finds my address ok - click continue to (I presume) proceed to the CC entry form and voila!

Well not quite.

"There has been a problem processing this request
Please use the refresh button on your browser to try again.

Thank you."

A few refreshes later, it is apparent that Waterstone's has no intention of working, sod it, for 20p more I can have less hassle at Amazon.