Ah - .texture files.
You will need one of the PEVSoft tools (Images2TGA).
Note: If the assets have a negative number at the start of the KUID, you will not be able to save any changes, so you will need to revert them to original.
You can download this from
http://members.optusnet.com.au/~villaump/pevsoft.htm.
Once downloaded and installed, run it once as administrator if using Windows Vista/7 - this will allow the required files to be created.
If you do not get a folder selection box appear, click Setup, then OpenWith - this will then ask for your TS2009 folder, as well as a TS2010 folder (if you do not have TS2010, click Cancel on the box that asks for the TS2010 folder).
Once done, click the Options menu, then click each item in turn until all of them have ticks next to them.
Close Images2TGA, and restart Content Manager if it is already running, if not start it normally.
Right-click the affected assets - you will notice a new menu option: Open With. Select this menu, then click Images2TGA.bat - the process will take place automatically, and will tell you when it is done.
The .PM references should only be appearing as warnings - if they are appearing as errors, reply to this post.
The shadow mesh problem will require QuickShadows, available from the same place, as well as using Content Creator Plus to edit the config.txt file - once you have sorted out the image related problem, I can then advise on dealing with the shadow issue.
Shane