When a term is imported from a text file in a term list, it is truncated at 255 characters. When the term is a journal name with the various abbreviations, it can be longer than 255 characters.
It occurs several time in the list of journals I publish:
http://www.ese.u-psud.fr/epc/conservation/SJI/Endnote_Journals.zip
This bug has been reported to Thomson team and I hope that it will be corrected in the next beta.
Marc