I put the path after the ;.; so it would not override a dll in the current directory.
That is probably a mistake. If you have an old copy of a DLL in a program directory, and you happen to start that program first, you will load the old DLL. That program will probably work fine. Now, if you start another program that requires a newer version of that DLL, it might not work because the older version is already loaded. That can get really confusing because if you start the program that requires the newer DLL first, both programs will work because the newer DLL will be loaded.
It is important to eliminate ALL down level duplicate DLLs, everywhere on your system, if there is any possibility that they will be used by something. When you use RPM/YUM, it is ASSUMED that the ONLY copy will be the one that YUM controls. Therefore, the .; entry should be second, to reduce the possibility of using the wrong DLL (it is still not impossible). The .; entry should only be used for program specific DLLs, and those should only be in the program directory, and there should be no duplicates, so it shouldn't matter where the .; entry is located in the LIBPATH statement, other than to reduce the time required to find it.
Note that some programmers have INCORRECTLY included DLLs in their packages, thinking that they are helping the user. The end result is duplicate DLLs, at different levels, and much confusion. The most common seem to be PTHREAD.DLL, and MMAP.DLL, but there are others.
I will also mention that QT programs store information about DLLs (and other things) in %HOME%\.config\Trolltech.ini. If you move a program, or a DLL, QT programs can quit working because the entry is now wrong. The fix is to delete the %HOME%\.config\Trolltech.ini file. It will be rebuilt. That "feature" has caused problems, for me, more than once. I haven't done it, yet, but I am going to simply delete it at every boot, if it causes me trouble one more time. Apparently, it will cause QT programs to take a fraction of a second longer to start, but I can live with that, while the complications can be a PITA, usually at a very inconvenient time.