Note: I am neither a Mac user nor a Clie user. This information is based off of what I have read, and not what I have experienced.
The latest version of Palm Desktop for the Mac is currently 4.2.1D. This is for Mac OS X 10.2.6 to 10.4. However, it appears to only be compatible with: Treo 600, Treo 650*, Tungsten E2, Tungsten T5*, Zire 72*, Zire 71, & LifeDrive.
http://www.palm.com/us/support/macintos ... 1revd.html
Palm also has 4.2.1A still available. This claims to be for Mac OS X (version 10.1.2 or higher) or Mac OS 9 (version 9.2.2 and higher). It also claims to be compatible with: Tungsten™ C, E, W, T, T2, T3, Zire™ 72*, 71, 31*, 21, Zire, Palm i705, m500 series, m100 series, VII series, V series, III series, and PalmPilot handhelds. Therefore I would think this is more likely to be compatible with your device.
http://www.palm.com/us/support/macintos ... sk421.html