I am having the same problem and turning PHP debug on produces nothing.

BTW, what is LF?

I know it has to do with Bulletin 2.0.3 since its RSS is having the same error message.

I looked all over the files under trust_path/modules/bulletin and language files. So far I have found nothing and the error message remains.

The weird thing is that IE has no problems at all.

[edit]
- problem solved
It turned out that I have left some whitespace in an included file in mainfile.php - Xoops original would not even run with any whitespace in that file, Xoopscube apparently is more tolerating with whitespace but in this case it is not a good thing at all.
I spent a couple of days trying to figure out where the problem was and only stumped onto it when I tried to validate the theme.
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