Strange...
whithout more info, I can only speculate.
Option 1: the loader can't find SDT.swf:
You have to extract evrything fram the archive for things to work and you musst keep the folder structure complearly intact. So do'nt move anything around, or change any filenames.
After opening the loader.swf, it expects the SDT.swf to be in the same folder.
Option 2: Your download was currupded and SDT.swf is broken. Csn you still open SDT.swf manually? Try redownloading.
Option3: Maybe a problem with user rights keeps the loader from opening SDT.swf. Where dit you extract the loader? try extracting it onthe desktop.
Also it's usually he best to use a Standalone Flash projector to runthe game,
If none of this helps, I have no clue.
edit: godd to hear you made it work.
However, Idon't know wy it only works sometimes.