The Cut and Copy buttons are enabled and appear to function correctly, however clicking the Paste button does not copy text into the Script Editor window.
Cause
This is a known issue.
Solution or Workaround
The ArcView 3.x Windows XP Patch for ArcView 3.2, 3.2a, and 3.3 fixes this problem. Download the patch through the link ESRI Patches and Service Packs in Related Information below. Click on ArcView 3.x, and find ArcView 3.x Windows XP Patch. Follow download instructions.