I find it curious that no one noticed except you and me. I agree it is quite annoying, but to MStarDict's defense I must say that I have looked into this and found that the problem is with the dictionary itself. The main .dict file contains IMG tags referring to the bitmaps with spurious non-printable characters in the file names. Example, <IMG src="_7e3d5890.bmp_">, where _ stands for non-printable chars 0x1E and 0x1F.

I have managed to remove the chars in a hex editor but then the index file did not match and MStarDict crashed on loading the dictionary, so I reverted it back to the original. If anyone could tell me how to fix the index that would be greatly appreciated.