One thing to sort out before doing anything is just what a resource map is.
This gets a little geeky (even for me), but...
wikipedia wrote:
The resource fork is a construct of the Mac OS operating system used to store structured data in a file, alongside unstructured data stored within the data fork. A resource fork stores information in a specific form, such as icons, the shapes of windows, definitions of menus and their contents, and application code (machine code). For example, a word processing file might store its text in the data fork, while storing any embedded images in the same file's resource fork. While the resource fork is probably used the most by applications and other executables, every file is able to have a resource fork.
In the structure of the resource fork, there is a piece of data called a "resource map" which stores the positions of resource data items. This can be used to allow random access to resource data based on the defined IDs and names. The resource fork can be thought of as consisting of essentially two objects, the resource map and the resource data itself, but in fact each data type is a hierarchical structure which stores multiple items of data. The format in which the information in the resource data is stored is defined based on the types of information, which are known as "resource types." Resource data often references other types of data.
http://en.wikipedia.org/wiki/Resource_fork
One thing which might be done first is to repair permissions-- either through Apple's Disk Utility (from the install disk) or with a third-party utility such as DiskWarrior4-- which now includes a repair permissions feature. DiskWarrior (for me, anyway) tends to do a better job overall at rebuidling forks and maps.
If, however, there is some inherent dysfunction with how DP 4.61 imports audio under Panther, then and only then should you consider updating to Tiger.
FYI-- there was a period of time in Panther in which I could not get audio import via the menus to work properly. This seemed to have improved as Tiger was updated. Among the symptoms was the inability to preview audio before importing from the soundbites' Import window, and batch importing of audio samples through this same window. Dragging audio directly from a CD, CD-ROM, or hard drive into an appropriate and active audio track became the workaround.