I check with robtex and it says that currently my IP isn’t listed in any blacklist.

Yes, my ISP reset my IP every 24 hours and everytime I connect.

I’m not behind router. Like what I’ve said before, I’m using EVDO wireless modem for my internet connection.

Checking again today. I can enter Piriform website but still unable to enter their forum with the same error message. This is really weird.

Correct me if I’m wrong, theoretically if I can enter the domain (piriform.com) then there shouldn’t be any problem for me to enter the sub domain (forum.piriform.com) right? (unless there is some rule or restriction applied against my IP number)