I have this problem and maybe it's something really obvious, but I have not been able to figure it out.
I'm working on a form api form on Drupal 6, and for some reason on my development machine (my local computer), on which I'm using xampp, the $form_state['storage'] NEVER persists. On the rebuild of a form (e.g. going to the second page), the key is just not there and I lose key information from the first page (and from elsewhere). Does anyone have any insight into this? It seems to persist into the submit handler from the first page, but doesn't make it to the rebuild.
Im facing a problem with a webshop build in drupal and the ubercart module.
I was trying to work on a different problem and empty the cache but then the product filter and the calculating price of shipping stopped working and the CSS file was no longer included. I really cannot find out what the problem is. As days got by i did my best to find out what was going on.