To the OP...I understand your plight. I have no resolution, as I encounter the same issue from time to time. ---Don't know why--- I have a TF300T 32gb storage, w/22gb avail, and a 16gb SD Card, w/9gb avail. I am trying to install an 8.46mb Google Earth app that results in the same error message as you. So.....the posts/replies telling you to use this, use that, do this, do that......so far I have previously done all of those. The don't help.In the past, when I've had this issue, it only seemed to work itself out after I installed another app, and then came back to install the problematic app. Virus Scanners (AVG and Avast), System Maintenance apps (CleanMaster, MemoryBooster and CacheMate) have not resolved it.Again..I have no resolution, just a suggestion: try to download a small app, e.g. ebook reader, or a free ebook thru Kindle, Nook or other app (not Google PlayBooks). I think the system (Android) remembers (in a "secret" cache) that problem install, and needs a "rewrite" via another install. So...if you know that your memory (shown in System/Memory) is at a good level free, this may (or may not) work for you. It works for me, but I came here trying to find if there are any app suggestions, or Settings suggestions, that have been proven to work "flawlessly" every time. R/S.....
Okay....Three hours after my initial response to the OP's problem, I came across a posting by user/member "nazty4"-- I think. His response was this: Go to System/Data/App.....and find the old install leftover, for the program you are currently trying to install. It should be only one file....*****.odex. Delete it. Try reinstall again. But, my TF300T is rooted, and I have a File Manager/Explorer that shows my Root and Rooted Files. Android File Manager does not. Just FYI.