MPASM works just fine with any config directives the PIC has, but they are different than config directives the PM assembler expects. See the thread I linked to above for the details on config use. Melanie does a nice job explaining this.

I don't have a PicKit2, so I can't really say how it works, but I would assume it can read & use config options embedded in the .HEX file, or give you an over-ride option.

Maybe someone else here familiar with the PicKit2 can comment on this one?

Look in the 16F628a.inc file in your PBP directory. If you use PM, it uses the top config defaults. If you use MPASM, then the 2nd default config options are used.

When you insert a bogus config directive in your code, it isn't used, and of course it has no bearing on what config options will be embedded in the .HEX file.

Read the thread by Melanie I linked to earlier. It is well worth the time.