I have received warnings
Warning: array_flip() [function.array-flip]: Can only flip STRING and INTEGER values! in DrupalDefaultEntityController->load() (line 178 of /home/domainname/public_html/includes/entity.inc).
Warning: array_flip() [function.array-flip]: Can only flip STRING and INTEGER values! in DrupalDefaultEntityController->cacheGet() (line 355 of /home/domainname/public_html/includes/entity.inc).

After reading this: http://stackoverflow.com/questions/4798047/array-flipcan-only-flip-strin...

I did a search for "_load(array", and came up with pathauto.inc line 93
return path_load(array('pid' => $pid));

When I deactivate the pathauto module, I do not receive the error. I will play with the module later and see if I can fix it. I thought I would let you know.

Comments

According to API doc, I tried to replace return path_load(array('pid' => $pid)); with return path_load($pid); but the error is still there.

@MtRoxx did you find another way to solve this issue ?

For now I shutoff pathauto.