Upgrading Drupal

I've just finished upgrading my site from 4.7.5 to 5.1.

I've hit a few issues. I'm not sure how to correct the issues though.

I get the following errors:

    * user warning: Table 'DOMAIN_drupalkelly.node_type' doesn't exist query: SELECT nt.type, nt.* FROM node_type nt ORDER BY nt.type ASC in /home/DOMAIN/public_html/DOMAIN/includes/database.mysql.inc on line 172.
    * user warning: Table 'DOMAIN_drupalkelly.blocks_roles' doesn't exist query: SELECT DISTINCT b.* FROM blocks b LEFT JOIN blocks_roles r ON b.module = r.module AND b.delta = r.delta WHERE b.theme = 'garland' AND b.status = 1 AND (r.rid IN (2,3,4) OR r.rid IS NULL) ORDER BY b.region, b.weight, b.module in /home/DOMAIN/public_html/DOMAIN/includes/database.mysql.inc on line 172.

The above appears at the top of every page. Also, no blocks are working it seems. If I try to access the blocks admin page I get a long list of these errors:

So my service host upgraded the PHP engine, which caused my site to forget who you are after logging in. You get one page view, then you're forgotten. This, of course, is a problem. They told me to upgrade. So I followed the instructions (did not do the database update... do I need to? I didn't think so) and when I go to the new site through the URL I've been using all along, I get a 404. If I use one of the ?q=node/ links then I get "Fatal error: Call to undefined function filter_xss_bad_protocol() in /{this is the file path...

I had a chinese content blog and I was trying to do an upgrade. I exported the database into a .sql file, and dropped the whole database (This is really stupid, I leant my lesson). So now all I have is this .sql backup file.

I imported this .sql later and I found all the Chinese characters can not be displayed and replaced with "?" instead. I then opened this .sql file in IE with utf-8 coding, and found out the content in the "catch" section become a series of hex numbers, such as: 0x3c703e4142432062726f616463617374696e672e2e2e3c6272202.....

I'm not sure if this is an error with the upgrade or sheer ignorance on my part, but I've been having issues with the "Public Checkbox" on all of my content types after upgrading to Drupal 5.x. I do not remember this box needing to be checked with 4.7 -- as the text reads to "Only check this box if needed."

Why does my sites suddenly "need" this box checked? Is there a setting somewhere that I've missed? Can all of the content be set to automatically display regardless of this setting, or can I set Drupal to automatically check this box?

I'm trying to upgrade my captcha and textimage modules in Drupal 5.0. After overwriting the respective module directories with the newer versions, I attempt to run the update.php script and receive the following error:

An unrecoverable error has occured. You can find the error message below. It is advised to copy it to the clipboard for reference. Please continue to the update summary

An HTTP error 404 occured. update.php?op=do_update

The update summary page provides the additional info:

Hi All,

I installed Drupal 5.1 to new directory; also my existing system uses 4.7. Now I want to transfer my existing content(4.7) to new system(5.1). How I can do? Thanks a lot.

Best regards,
Treo