Unless I am missing something, the problem with the wishlist system is that books have to match exactly on the ISBN.  So, if I have a different edition or printing of a book and I see that someone has essentially the same book on their wishlist, there is no way to match up and there does not seem to be any way for me to contact that member to say, "Hey, I have the book you want" even when they might not really care that my edition has a different picture on the cover even though it has the same words inside.

So, does anyone have a solution to this problem?

There is a box you can check in your Settings section for PBS to send email alerts about WL'd books with different ISBNs that have been posted.  Plus, you can advertise in the Book Bazaar about your book having a different ISBN. 

Here's the link to the Wishlisted/Different ISBN thread: http://www.paperbackswap.com/forum/topic.php?t=123221

You can also tag the WL books with a note to check your ISBN.

Make sure it's the same version.  Many people come on here thinking they have a WL book when there are many copies of their version available. If it's available in paperback and the hardback is WL-most likely they only want hardback.  Same thing with audio and large print. 

Once I had a paperback that had a really long WL line for one version.  My ISBN had the same cover, #of pages and everything but a dif ISBN.  There was 1 posted already.  I posted mine and then I tagged the WL one "2 posted under this ISBN". It was ordered almost immediately.

So, does anyone have a solution to this problem?

It's not a problem, as far as I'm concerned. With very few exceptions, I've wishlisted the specific editions I want. Sometimes I wishlist alternate versions of a book, but in those cases, I want only one of those specific editions. When I get one, I delete the others.