Tool v1.12 was release to the homebrew community for PSP . So if you are using the old version of ISO Tool , Then is best to go ahead and update to the latest version which is ISO Tool v1.12 as of March 17 of 2010 .

This is what the developer had to say about this release of ISO Tool v1.12

Was pointed out in comments, the top “.” Measures conducted
Support in the software, so when you rename, UMD_ID.csv change is not required

*1.12
[UPDATE] When renaming the beginning. “” If, “” (blank) to add to the beginning