Scheduled task runs Powershell - UserProfile\Temp full of PS1XML, PSD1 and PSM1 files

Hi,

on our Exchange 2010 servers I'm running a small powershell script which sets the Mailbox Retention and OWA Policy.

The script works fine, but after 2 months we figured out that the User profile of the user which runs the script as a scheduled tasks gets filled with hundreds strange folders in the temp directory. One of these folder contents I post here:

    Directory: C:\Users\is124\AppData\Local\Temp\tmp_0b8ec8ce-7a7f-428f-acd2-fd390520b3dd_lu1mmlns.zuw

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
-a---          5/2/2014  10:40 AM     506750 tmp_0b8ec8ce-7a7f-428f-acd2-fd390520b3dd_lu1mmlns.zuw.format.ps1xml
-a---          5/2/2014  10:40 AM       1246 tmp_0b8ec8ce-7a7f-428f-acd2-fd390520b3dd_lu1mmlns.zuw.psd1
-a---          5/2/2014  10:40 AM    1368032 tmp_0b8ec8ce-7a7f-428f-acd2-fd390520b3dd_lu1mmlns.zuw.psm1

How can I stop this messing up? Do I need to create a new scheduled task which cleans the folders?

Thanks in advance :)