The issue here is that the initial tempo of the module is set correctly, but then in the first pattern the tempo is immediately overwritten with the same value. As the tempo exceeds the supported parameter range (0-255) after conversion, the song no longer plays at the correct tempo.

As of r18741 there is now a workaround for this situation by using OpenMPT's X-Param extension to write the high 8 bits of the tempo to a different pattern cell. It won't work with all MEDs using high tempos but it will fix this particular file.