Are you using any sort of proxy?
In the past, I have noticed when using certain proxies (that I assume are popular with comment-spammers for some reason) I get bounced from some sites because the IP has been associated with comment spam.
That is weird. I deleted the two threads you asked me to but didn’t suspend. Perhaps a glitch in the system with doing that. I am not at a computer right now. But will try and find out what happened ASAP and update you.
I bet that in some sort of roundabout way this is the cause. I’ve had this happen (elsewhere) even when getting exit IPs that belong to regular US ISPs.
I deleted the entry (and I think @falcor explicitly allowed it, but I prefer to delete those entries if they are problematic) so you should be OK now.
Whenever a spammer is deleted via the “Delete Spammer” staff button, their IPs are automatically blacklisted for a year (or more, if they keep matching). My guess is that somehow happened in this case.