Anyone knows how to resolve the unreadable codes?

I’ve been upgrade WP from 2.5.X to 2.7 just a few hours before my hosting move all data to a new server with WP 2.6.3 installed, but the data move is the one before upgrading. The problem is all my contents becomes unreadable codes. I’ve tried to resolve with phpmyadmin to alter all the collations from “Swiss….” to “UTP8”, but nothing heppends, then try other ways, such deactivate all the plugin, upgrate WP to 2.7, bad luck for me. nothing happends at all.

So, what’s the cause for me, how to resolve it?

Thanks for everyone’help in advance.

OOp. the contents in my site are in Thai, English and Chinese