With the IBM Rational ClearQuest Native, Eclipse and Web clients you cannot attach files of the same name to a record, whereas you can through the ClearQuest API.
Inconsistency exists between the ClearQuest API and the GUI clients for uploading attachments of the same name to records. This issue was identified as a product defect under APAR PK59690.
Resolving the problem
The API attach issue remains a product restriction. IBM Rational ClearQuest GUI clients already look for duplicates.
Modify your script to avoid uploading of attachments of the same file name through the IBM Rational ClearQuest API.
Add code to your script to verify if an attachment file name is duplicate, before the script calls the API.