What text? What font? What appearance settings? Is it outlined or live text? If outlined, have any compound paths and groups been properly sorted and released, where necessary? Are there any bitmap effects applied to the artwork?
I've seen this on my machine. The AI file came in as black text on black backgrounds.
User error in AI, changed text color..
I really have no idea what the issue is.. I did the following. Copied my text from notepad, pasted it into AI, changed it to 'arial', TYPE > Create Outlines, ungrouped the text, grouped each word, went to LAYERS > OPTIONS > Release to layers (Sequence), in AE I imported the AI file as 'Composition - Cropped Layers. Then it just came up as the blocks. As a simple test I went through the same process with a new file with simple the word HELLO and it worked fine.
The only cause I can think of is maybe because I copied the text from Notepad? The font I originally chose in AI was Helvetica Neue. Maybe the font wasn't applicable to AE?