This would be an interesting question to ask at XDA, where all the devs are. I disagree that these are web sites timing out, though.
The TF700 has only 1GB of RAM. IMHO, it should have 2GB. Add low RAM to the popular understanding that ASUS screwed up its software development, and it's understandable that, for now, the Transformer will be less responsive than we would like. When I was stock, I saw that browser message ALL the time. Running CleanROM instead of stock, I see that message (stock browser) once in 8 hours of use, if that.