As i suggested you earlier - assignment of position change category (PCC) to update type is already predifined for simple and standard configuration!
you are not able to set PCC to DBT_E001 update type because you won't see this update type in configuration! It is alreadry hardcoded, predifined to E001 PCC.
DBT_XXX update typs - XXX it is also position change category. See table TRLTS_PMCAT.
Why do you want to assign PCC to interest received and to SAM3010? did you similate your deal with interest received and SAM3010? Is it ok or do you miss something in your accounting?
General rule about PCC - if you miss something and need more difficult acconting - use position change category! in all other cased - predifined configuration is ok.