MT Comment Forms Used for Spam?

I glanced through the MT Support Forums and didn't see anything in regards to this, but I didn't have a whole lot of time to look.

Here's what's happening: Every couple weeks, I'll get a few comments that do this type of thing:

In the author field: "angelrrsmr@aol.comTo: angelrrsmr@aol.comFrom: angelrrsmr@aol.comSubject: kvlP(C87BA01E,author)ZOl"
In the e-mail address field: "angelrrsmr@aol.comTo: angelrrsmr@aol.comFrom: angelrrsmr@aol.comSubject:"
In the URL Field: "http:// angelrrsmr@aol.comFrom: angelrrsmr@aol.comSubject: aw(C87BA01E,url)OY4QK1FA2lmq5DIVMRq28RS0KB Ed WPJEfnH3l7M06xz9."
In the comment field: "body"

Herein lies the problem: When I get my e-mail notification for comments, I notice that the "To:" field not only has my e-mail address, but "angelrrsmr@aol.com". They come out looking like this:

A new comment has been posted on your blog UtterlyBoring.com, on entry
#1602 (Want a really long e-mail address?).
http://utterlyboring.com/[snip]#2531

IP Address: 137.164.143.111
Name: angelrrsmr@aol.com
To: angelrrsmr@aol.com
From: angelrrsmr@aol.com
Subject: kvlP(C87BA01E,author)ZOlL2KUa

bebrrG5sr6xaIp3ejB Ik

Anybody else run into this? I've posted this on the MT forums, but feel free to comment here as well.