Recently active topics in PBwiki tagged with e-mail

My students are using the "contact wiki owner" link to send me an e-mail telling me what they learned during a project. I have about 20 kids in the computer lab at a time. The first 10 or so contacts go through just fine, and then something happens--the next few kids will keep getting "Sorry, the verification word you entered was incorrect. Please enter the correct word"--even when the letters are correct. I sat down myself today and entered the verification letters for one student ten times in a row, but kept getting the error message. I've tried clearing the cache, changing computers, and switching browsers, but nothing made a difference. Every field was filled in, and the e-mail they were using was valid (since it was mine!) Why is this happening? Can pbwiki handle only a certain number of "contacts" at a time? It's making us crazy, since these are young kids (7 and 8 year-olds) and their frustration at having to type in verification letters over and over is considerable.

I've got a problem. I've stopped using my first e-mail account and want to switch the notifications over to my new one but I don't know how.