I'm using 1.3.8a

Upgraded PHP on the server from 5.1.6 to 5.3.8

All is well with all websites, except blank white pages where there should be zencart installs.

Found this....
http://www.zen-cart.com/forum/showthread.php?t=140960

Thanks!

Installed patch(correctly) - websites back, but admin is still blank.

any possible solutions appreciated.

(we had previously tried to upgrade Zencart, but there were several upgrade errors, product descriptions disappeared. So we went back to 1.3.8a from backup, so I don't fancy that as a solution - obviously needs to be done at some stage, but for now I just want admin back if possible)