ok here I also face same problem like you all.
Now I found a easier solution for it.
When I login SEA region, I try so many time it keep fail on downloading the content. Now I change region to NA, it download and finisih very fast, now with this , I able to play in either SEA or NA. so I suspect IAH server not as good as US server that why it keep drop when we downloading the map.
Hope that this can help you all.

IAH dunno have knowledge ppl to setup server and maintenace it?
dunno why NA can work well than this.
After a few game, I feel that NA server quite well, I not feel any lag at there.
IAH one most of the time when game start, we issue worker, it mostly delay at that time but I not facing delay on NA when game start.

anyway for me to run old version 1.0.3 starcraft?

Is that when we start launching the game, it only show login screen? the left side dun show region at all, we have to login then logout ,it only appear the region button?