Editing product with bulletpoints deletes all info when clicked in admin

Having upgraded 1.3.9 to 1.5.1 editing product with bullet points deletes all info when I clicked in admin. Its all showing before I click it. The process of going to edit it clears all the fields on the page.
I have changed the character set back to latin1 in config files in the past.

I have changed the character set back to latin1 in config files
Have you also changed it in your english.php file??

yes both in main language directory and inside the template just to make sure.

getting this error log Invalid multibyte sequence in argument in admin/includes/modules/product/collect_info.php on line 401

line 401

Exactly how did you upgrade?

Basicly
Made a copy of my site and uninstalled mods keeping note of what uninstall sql files needed to be run.
Made new site and connected to that database then ran upgrade.
Installed mods and checked they worked taking note of all sql to run
(i didnt check the current problem so it probably existed here on test site)
Took down live site and repeated the process on current up to date database database.

Just tried changing everything I had edited back latin1 wise and the description field still disappears. Its working on public pages so if we want to update a product we have to open it on front end and copy and past that description into admin area and remove symbols like bullet points. Once you update it the description stays. If I update with a symbol it will disappear again once I try to re edit it.

You failed to mention the files

How did you upgrade them?

For the upgrade?
New build of 1.5.1 with new template. Only thing I wanted from old was customers and products etc

Only thing I wanted from old was customers and products etc
So you did not import a complete old database and upgrade it???

Mistake

Which HTML editor are you using in your Admin?

CKEditor? If that is what you mean but normally just use plain text. Both ways have the error.