In the archives i found that jongware had the same problem with bookmarks in CS3, but no solution. So here i am hoping for an answer.
I have something like the following working code for adding my bookmark:
h = app.activeDocument.hyperlinkTextDestinations.add(myPara);
bm = app.activeDocument.bookmarks.add(h);
bm.name = myString;
When i make multiple bookmarks based on paragraphs the first bookmark ends up with the name "Anchor 1", the second one gets the correct name used in myString, the third one ens up with "Anchor 3", and so it goes on.
What happens behind the scene:
I start when i have 2 bookmarks. One with the name "Anchor 1" and the second is "myString for bookmark 2". I undo the rename and i get "Anchor 1" and "Anchor 2". Then i undo new bookmark and i get one bookmark "myString for bookmark 1". So i get the correct name.
When i let the script run step by step in debug-mode i don't even see the name getting changed form "Anchor 1" to the string on any moment.