Turning On CSS and JS Aggregation breaks site in IE suddenly? Anyone else?

Anyone else see this before?

Upgraded a working site to 7.19 and the site was broken when viewing in IE
The pages seemed to be free of CSS and JS

Was given two errors in IE citing the cached JS file Message: Invalid character Line: 1 Char: 1 Code: 0
And jQuery Undefined

Spent some time narrowing things down, removing scripts one by one, hard coding scripts, flushed caches etc...

all JS files are unmodded and worked perfect before upgrade, only thing changed is Drupal core upgrade.

Turned off JS Aggregation and hard coded the JS files into the theme the errors are gone but the CSS is still not rendering.

Turned off CSS Aggregation and site works fine.

And all this only happens with IE all other browsers load the page perfect even with Aggregation turned on...