This may be an odd place to post but AVPlayer HD has a help forum that seems impossible to post in. The input buttons are in Korean and don't function.
The problem srt subs play fine in VLC or Media Player Classic.
But in AVPlayer HD:
Some movies with .srt subs work on the first try.
Other movies I can resave the .srt subs in .smi format and then they work.
A couple of movies simply will not accept the .srt files in the original or new format.
What is the difference in the .srt files? (I know about matching the .avi and sub file prefix.)