Importing MTS files in AE CS5.5 in iMac

Hi -
This topic has come several times int he past i am sure, but i have been having aweird situation. With my Adobe AE CS5.5 installed i was able to drag and drop MTS files from my Sony camcorder, but of a sudden it stopped working and it syas it cannot render the MTS files anymore. I thought i might have corrupted something ( i used a utility to clean my Mac and removed a lot of junk file), so i reinstalled the full set again, but still i have the same issue.

Its just that it was working all fine and suddenly it says it cannot import MTS files any longer. Any ideas on what the issue could be?

Any help appreciated.

Vimmy