Hi Dimitry and Chris,
for some reasons, 0.9.0 beta13 and 0.9.0 beta14 contain an outdated Windows launcher, which does not have the parameter "arguments = "-Xmx256M";".
The most up-to-date Windows launcher containing the butterfly icon can be found in the following patch; it has already been used in
0.9.0 beta8 unless I am mistaken. The launcher has around 9 KB, unlike the old one having some 7 KB.
If need be, we can increase the value of 256M to something larger, but I just succeeded to open three 10 MB maps at the same time with
0.9.0 beta 14, just that I started it using the correct launcher.