Does it matter which devices you delete?
It might be a database corruption issue.
If you do not have a lot of data saved, I suggest
you to try
Exporting the Data
RME->Administration->Inventory->Export to File:
give a filename, ie. inventory.csv
Choose options: Version 2 and Comma Separated Value
Format
take the output file and save a copy on your client
machine.
Open the file using a Spreadsheet program, ie. Excel
delete any entries you don't want.
Save the new file with a new name, ie. update.csv
Then follow the below link to reinitialize the RME database:
http://www.cisco.com/warp/public/477/RME/reinitialize_rme_db.html
Once you feel the GUI is running properly, move a
copy of the new file, update.csv to the same location
as the original file you exported.
/var/adm/CSCOpx/files/inventory
Then in the GUI, goto:
RME->Administration->Inventory->Import From File
hope that helps