festizio from #ps3test has made a nice writeup on how to solve the backups issues in Kmeaw CFW especially the freezing issues after running PS3 games in external hard disk. It is actually file permssions fix in PL3, now it has made to be compatible with Kmeaw CFW. Read this, festizio has made a good explanation:
It seems that alot of folks are having issues installing and running backups on there Ps3′s due to the bug in PL3 that effects file permissions. Here is what I have been doing to get around the black screen hangs and disc read errors.
1. fire up multiman, blackb0x, whatever ftp & transfer your backup
2. run your lv2 pkg of choice
3. run the fix permissions app that is installed from running the package located here – http://www.mediafire.com/?cyi363utdttieux
The app will go through the HD and correct the file permission errors that come with using PL3. I have been using this method after each game backup I install,
however if you install (ftp/copy) 5 at a time the app only needs to be run once and it will fix all 5 games as it does its magic to the entire drive.
Now as far as USB, hampster driven HD’s etc I can not say as I do not have any of the above so I have not tested it myself.