It is your decision and we will honor it even it it makes things more complicated Please remember that you always can just make copy of forum and give us access to test instance, not real forum.

Please fallow instructions which we already gave you. You do not have to set echo after each line - find how binary search is working. Put some in the beginning, some at the end, some in the middle. Check which are shown which not, put few between last one and the one which didn't shown, and so on. This way you will determine where code breaks. Another hints - use URL for RSS2 and set echos in functions for RSS2 (lot of code is not used at all). As I already wrote you - we know our code and know how and where to look efficiently. For you can be easier if you just find occurrences of RSS2 in code. Please start from the beginning (look in hints before) - it can be something before evaluation goes to RSS2 specific code.

Also before all of that please check do you have any other plugins working on hook external_complete and disable it temporarily to check does some of it causes conflict.

Please let us know about your results.