the ebuild for dev-cpp/asio-0.3.4 can savely be used to emerge dev-cpp/asio-0.3.7
It is also worthy to note that 0.3.4 cannot build against GCC 4.1.1, where as 0.3.7 can. However, it's impending inclusion into Boost may make it not worth it.
Well, asio won't make it in boost-1.34... and boost-1.35 is still far, far away :) Fixed in CVS, thanks.