A few glitches since upgrading to RC3

Updated my site to RC3 last night and noticed a few issues. I don't know whether they are specific to RC3, or whether its just a case of I was carefully looking out for problems at that specific moment:

1. Embedded images in forum posts have all been made thumbnails.

2 Before logging on, members who uploaded their own avatars are seeing the initialled avatars by default not their own avatars.

3. Oddities when inserting a table into a post. If you type text, then select a table and multiple rows, say 20, to go into the table, the text is either moved below the table or deleted.

Quote from Alexander Ebert

Which version were you using previously? Were these images inserted using the "original" size before?

Using RC1 previously and the images were inserted full size.

Quote from Alexander Ebert

This sounds like you're disallowing guests from viewing avatars, in which case it will fall-back to the default avatar. Since 3.1 this is no longer just a silhouette, but generated avatars based on the username.

No, I've not done that or changed any setting. The guest usergroup can view member's avatars, see here:

One of my mods has informed me that the email notifications he received is showing the avatars as initials as well.

Quote from Alexander Ebert

I'm sorry, but can you rephrase the part about the selected table with the rows please? Did you mean that you want to insert a table, or insert a table into a table? Or did you mean "a table which contains 20 rows"?

I inserted a table with 2-3 rows into a forum post and did not see any problem. I then created a new post and inserted a much larger table with 20+ rows and that is when the problem occurred.