Imagecache doesn't save filesystem (unless add ?param=$sometime to url), but shows images in browser

Image 6.x-1.2
ImageAPI 6.x-1.10
ImageCache 6.x-2.0-rc1

I updated my site locally on my windows computer to move from drupal 6.21 to 6.28 and also upgraded to php5.3.
Then i updated our server to php5.3 and dropped in the new install/db (and set the perms on the files/ directory) and noticed image_cache acting kinda funky...
The View that I have an imagecache preset doesn't seem to generate the images on the filesystem (but can see all of them on the webpage itself)...
I tried going straight to the image via url like http://www.example.com/sites/default/files/imagecache/dir1/dir2/image1.jpg ...
Still didn't generate and imagecache preset on the filesystem ...
then i add a param like so: ...image1.jpg?time=1234567890 and then the imagecache_cache() function actually runs and generates that single image...
Any idea whats going on? I put error_log outputs on every function in imagecache_actions.inc and imagecache.module, and when I goto the View, i only see imagecache_user run when i visit the View?

I turned off the 'Fast 404' module as I thought maybe taht new module was causing issues. BOOST doesn't cache images like that so dont think its BOOST.
Anything I can do to see why imagecache_cache() isn't being run?

Thanks!,
Ari