If you are executing the READ_TEXT during execution of transaction, did you [un]check the bypass buffer option, did you insure not to overwrite memory used by standard transaction, there is only one area in memory for a text (*),
Also if you need two texts, call the FM twice with different value of ID. You could also browse table TXHD to insure you have correct keys/parameters values.
Regards,
Raymond
(*) Look at FM as GET_TEXT_MEMORY, or import CATALOG from memory Id 'SAPLSTXD'.