Hi
This "
[Info] [16189] HTTPCache key=..." say that pagespeed can´t find the cached optimized resource and remember the failure this amount of time.
Maybe a file write permisions?
Make a request with debug enabled and take a look at the html code, debug messages are set as html comments.
These "strange things" you see maybe are the metacache data. Pagespeed stores not only the optimized resource but metadata about it.
^DEtag^R^RW/"PSA-12345678"Xà§^Rh^@p^@ this header tell me that IPRO is working.
IPRO is an "on the fly" optimizer, don´t rewrite url but you can see in headers a x-original-content-length
and some optimizations.
Optimized resources have an etag header like W/"0"
^MCache-Control^R^Kmax-age=300J^Z
This seem to be the origin cache-control header so the optimized resource lives 300sec on the pagespeed cache aka the resource need to be optimized every 5 minutes.