macOS Help Book: E-mail links not working

The Help Book files in my app were composed in HTML. In XCode 4 all of the links work except for links that should open Mail so my customers can E-mail me. In older versions of XCode when they clicked on links like these:

<a href="mailto:support@myapp.com?Subject=appname">E-mail support</a>

It opened Mail. Now it doesn't. Can anyone tell me why and suggest a remedy?

Update: I tried composing this page in BBEdit as HTML 5. I created it in Text Edit and saved it as HTML. I created a page with iWeb. I tried a lowercase 's' in "subject". These all create html with a capital 'S' in "Subject". I tried it with out the "?subject". It works in two browsers, all of the HTML editors, in fact in everything except in my help book. ???

kainjow said:

Last time I looked into this, they didn't work in 10.6 and possibly 10.5, can't remember exactly. Don't think I tested with 10.7 either since I gave up...

Click to expand...

They worked with 10.5. I haven't "upgraded" to 10.7 - Lion because I read such awful comments about it on the Apple store web site and because my right hand isn't great and I struggle with gestures. Particularly hard are the new invisible scroll bars with no up and down arrows. These are retarded anyway. I don't want my Mac to act like an iPad, iPhone or PC, but I digress...

I filed a bug report on this with Apple.