It looks like Blog*Spot may be another victim of Thailand governmental control.
Until we know what's going on, the best advice is to use a proxy server. If only Blog*Spot is affected, this should serve as a workaround.
>> (Update 5/22): It appears that the Thai government indeed has problems with Google right now. Discussion of the problem in I think Thailand is blocking Blogspot.com.
>> For diagnosis of the problem, let's start with a TraceRoute Log.
>> Forum thread links: bX-*00045
>> Copy this tag: bX-*00045