Tables, mark up and reading order

Examples taken from Making Accessible Tables with slight modifications.

Complex table using rolspans and rowspans for headers

Browser services
Browsers Op Gecko Safari IE
FF Moz
Browser Yes Yes Yes Yes Yes
Email Yes No Yes No No
IRC Yes No Yes No No

Same table with no header markup

Browsers Op Gecko Saf IE
FF Moz
Browser Yes Yes Yes Yes Yes
Email Yes No Yes No No
IRC Yes No Yes No No

Table markup affect the reading order?

Here is the screen reader representation of the second table (without markup).

Browsers Op Gecko Safari IE FF Moz Browser Yes Yes Yes Yes Yes Email Yes No Yes No No IRC Yes No Yes No No.

Based on the previous line, can you figure out whether Firefox has email support?