Backup manager takes a long time to respond

[AlbertoGA]

Hi,

When I enter to a subscription and clicks de "Backup Manager", the plesk panel do not respond.
I can see in the console the following processes:

# ps -efl | grep pmm
4 S root 25339 23245 1 80 0 - 15866 poll_s 10:08 ? 00:00:00 /usr/bin/python /opt/psa/admin/sbin/pmmcli --get-dumps-list
4 D root 25362 25339 15 80 0 - 36175 sleep_ 10:08 ? 00:00:02 /opt/psa/admin/bin/pmm-ras --get-dump-list --dump-storage=/BACKUPS_PLESK/ --type=domain --guid=f9db8d94-23d2-46a6-bf44-1ad96a694045 --id=90 --name=mydomain.com --session-path=/opt/psa/PMM/logs

And it is consuming a lot of cpu.
I've checked and follow the instructions of this KB:

http://kb.parallels.com/en/119499
http://kb.parallels.com/en/119509

And nothing changes.
I have plesk 11.5.30 on top of Ubuntu 12.04.4 LTS

Any help would be appreciate it.
Regards,
Alberto.