I'm an admin for our UBB Threads forums.

I discovered an apparent problem with our Users table and posted a thread about it here:

https://www.ubbcentral.com/forums/ubbthreads.php/ubb/showflat/Number/184614/page/1#Post184614

However, since that time, I've been copying UNCONFIRMED user records to a research table before they get automatically deleted and I thinks I've uncovered some commonalities that causes me some sort of concern that we may be under some sort of attack, or something nefarious may be happening.

Since 5/24/07, there have been 28 users register, but then fail to confirm the new ID. By our standards that is a LOT.
The VAST majority of all these unconfirmed users report having russian email addresses.
There are only 4 or 5 IP address that account for all 28 of these registrations.
In all cases, these fields have these specified abnormalities:
U_Display = there is a QUOTE symbol (") in front of word "threaded"
U_View = there is a QUOTE symbol (") in front of word "collapsed"
U_SessionId = this should be a 32 character alpha-numeric code, HOWEVER, for each of these users the entry is just a "0".
U_Approved = This should be a "yes" once confirmed, but I am unsure what it should look like before it is confirmed. However, for each of these unconfirmed users, the actual value is the first 8 characters of what I'm guessing alpha-numeric Session_ID.

Now at first it accured to me that perhaps there issome sort of character set issue going on. Perhaps the Russian character set is not being "read" correctly. In SOME of the records, the U_Location field is populated with these two words Ðîññèÿ
and Óêðàèíà. HOWEVER, not all are like this. The majority of the rest list locations such as Oklahoma, or USA, or GB, and yet they too display the same field anomalies (even though they also provide a russian email address.

I realize I could block the IP addresses, but I hesitate to do that because it is not hard to come from a different IP address, AND it robs me of the opportunity to understand what is happening here.

Has anybody seen anything like this before?
Are we under some sort of attack and if so, what do they hope to gain or damage?
Is this a character set issue, and if so, is there a way to fix the problem for these Russian visitors?