I just reinstalled my OS(w2k SP4) and of course, FS2002 as well. I replaced the fresh GAUGES and aircraft folders w/ the customized ones I have archived and all would be fine, except that I now get an error on a few a/c: "flight simulator failed to load some 3rd party software:
offender's name.GAU

You can still use FS, but your 3rd-party software will be disabled"
The message then repeats once for EVERY visible gauge on a panel from the file(s)

I have FSUIPC.dll installed and all those aircraft/gauges worked perfectly on my old install. They're also recognized w/o problem by FS utilities like FSACC and the like......

I'm perplexed, b/c there doesn't seem to be any common factor b/w the malfunctioning gauges that I can see: some are original, some aren't, and most of the custom ones still work. The only thing I noticed is that replacing the malfunctioning MS gauges w/ the ones from the CD DID make the error disappear, which makes me think there could be some sort of file attribute that FS doesn't like.

Thanks to anyone who can make sense of this.

I did try and install the GaugeSound.dll, but it doesn't seem to have any effect whatsoever(I already had fssound.dll). Could it be another .dll that had been installed in the root folder at some point? That in itself would be odd, since I NEVER had those errors before, even on the first a/c I installed. I did go back and check my archived stuff for anything that could fit the bill, but found zip.........w/ my usual luck, it was installed by something I got rid of and forgot about.

Thanks for the answer, dude.  

EDIT: after further search and testing, it seems that FSSound.dll is not being loaded by FS no matter what I do. FS2002.CFG does refer to it in the old modules section, but FS behaves just like it wasn't in the modules folder.

Does anyone know what's going on here?
FSSound is version 1.5.1, btw.