Locking down compile flags (/TC vs. /TP)

Hi.

I've recently imported a new project for me into the MS VC++ IDE (vc7,
..NET 2003).

There are a couple of different directories for libraries. Some of the
files need compiling with /TC and some need compiling with /TP.

For reasons unknown to me, the IDE is often appending /TP to the
compile command line, even after I use the properties *** to delete
it. After I do a build, the /TP is back again and I'm having a problem
locking down each file to the way I know it needs to compile.

Are there other settings in a configuration which cause /TP to be
appended even when I have specified 'Compile as C Code (/TC)' in the
Advanced ***?

The IDE seems to have a mind of it's own! I'm relatively new to the VS
IDE, so I may be overlooking something obvious to a more experienced
driver. I'd appreciate any insight into how I can lock down my flags.

Also, is there command that will allow me to examine a library file and
determine the calling convention it was compiled with?

Thanks to anyone who can guide me here :^).

.