Plesk GUI update problem

[roadrash]

PRODUCT: Plesk 9.5.4 on Centos 5.4 x86_64

Trying to update through GUI.
On my other (identical) servers no problem. But this one particular server keeps saying:

Unable to obtain the latest version of Parallels Products Installer: The required version '3.11.0' was not found on the server. This could happen because of configuration error at the download site. Failed to open the file /var/cache/parallels_installer/parallels_installer_CentOS_5_x86_64 for writing: Text file busy.

Does anyone have had this problem?
Any solution?

 

[roadrash]

solved...

Well, it seems the problem solved itself....

Now, almost 24 hours later, I click "updater" again and there is no problem anymore...
Als updated ok.

Possibly there were some files locked or in use by a process.