Illustrator CS classes not known

Question

Some of Illustrators AppleScript classes are not known in ScriptEditor, e.g. layer. The following results in a syntax error:
tell application "Illustrator CS"
open file "Space:Users:bernhard:Documents:Test.ai"
name of layer 1 of document 1
end tell
The reason is that "layer" is not recognised as an Illustrator class. The following works:
tell application "Illustrator CS"
open file "Space:Users:bernhard:Documents:Test.ai"
name of «class caLY» 1 of document 1
end tell
The same thing also applies to other classes.
GIF export options does not work, «class cGIF» does.
So what is the reason for this? I did not find anything on the Internet about this problem. So any help is greatly appreciated.
Bernhard
Dual 2.5 GHz G5, nVIDIA GeForce 6800   Mac OS X (10.4.7)  

Answer 1

The following code, as well as your - initial code, works correctly with 'Script Editor' v. 2.0 (43) and v. 2.1.1 (81).
tell application "Adobe Illustrator" -- Which is 'Adobe Illustrator CS2'.
open file "HD3:Users:dev:Desktop:Test.ai"
tell document 1
repeat with i from 1 to (count layers)
display dialog (name of layer i) as string
end repeat
end tell
end tell
Here, 'tell application "Illustrator CS"' resolves to 'tell application "Adobe Illustrator"'.
  Mac OS X (10.4.4)