Probleems with web ftp

hi, recently when trying to upload some files using the webftp service I get the following error:

An error has occured

Could not generate a temporary file.

The error occured in file /usr/local/ndn/web/webftp/includes/filesystem.inc.php on line 1734.

* function acceptFiles (/usr/local/ndn/web/webftp/modules/upload/upload.inc.php on line 239)
o argument 0: Array
* function net2ftp_module_printBody (/usr/local/ndn/web/webftp/main.inc.php on line 321)
* function net2ftp (/usr/local/ndn/web/webftp/index.php on line 58)
o argument 0: printBody

anybody know why? and how this can be resolved?

Thanks

Is this a persistent problem? I received a similar error very recently (a few hours ago) and now things appear to working fine.

Yes it seems to be persistent, I tried yesterday and again today same error.