IE 8 not creating cache pages

more information in case this helps:
with debug turned on and checking the log, this is what i get when i try to cache an IE 8 page:
you'll see that '[is_cacheable] => ' at the bottom returns no value.
whereas, in a page i cache from chrome or other browser, i get '[is_cacheable] => 1' and then more information.

--------------------------------------------------------
debug log from page from IE 8, does not cache:
--------------------------------------------------------
Location http://69.195.111.29/energy
Referrer http://69.195.111.29/balance
Message Array
(
[scheme] => http
[host] => 69.195.111.29
[path] => energy
[query] =>
[full_path] => energy
[base_path] => /
[query_array] => Array
(
)

[url_full] => 69.195.111.29/energy_
[url] => http://69.195.111.29/energy
[url_decoded] => /energy_
[base_dir] => cache/normal/69.195.111.29/
[filename] => cache/normal/69.195.111.29/energy_
[directory] => cache/normal/69.195.111.29
[normal_path] => node/20
[path_alias] => energy
[args] => Array
(
[0] => node
[1] => 20
[2] =>
)

[menu_item] => Array
(
[page_type] => page
[page_id] => 20
[path] => node/%
[load_functions] => Array
(
[1] => node_load
)

[to_arg_functions] =>
[access_callback] => node_access
[access_arguments] => a:2:{i:0;s:4:"view";i:1;i:1;}
[page_callback] => node
[delivery_callback] =>
[fit] => 2
[number_parts] => 2
[context] => 0
[tab_parent] =>
[tab_root] => node/%
[title] => Energy Technologies
[title_callback] => node_page_title
[title_arguments] => a:1:{i:0;i:1;}
[theme_callback] =>
[theme_arguments] => Array
(
)

[type] => 6
[description] =>
[position] =>
[weight] => 0
[include_file] =>
[href] => node/20
[tab_root_href] => node/20
[tab_parent_href] =>
[options] => Array
(
)

[access] => 1
[localized_options] => Array
(
)

[original_map] => Array
(
[0] => node
[1] => 20
)

[status] => 200
[extra_arguments] =>
)

[is_cacheable] =>
)

--------------------------------------------------------
debug log from page google chrome, cache working:
--------------------------------------------------------
Location http://69.195.111.29/balance
Referrer http://69.195.111.29/careers-culture
Message Array
(
[scheme] => http
[host] => 69.195.111.29
[path] => balance
[query] =>
[full_path] => balance
[base_path] => /
[query_array] => Array
(
)

[url_full] => 69.195.111.29/balance_
[url] => http://69.195.111.29/balance
[url_decoded] => /balance_
[base_dir] => cache/normal/69.195.111.29/
[filename] => cache/normal/69.195.111.29/balance_.html
[directory] => cache/normal/69.195.111.29
[normal_path] => node/36
[path_alias] => balance
[args] => Array
(
[0] => node
[1] => 36
[2] =>
)

[menu_item] => Array
(
[page_type] => page
[page_id] => 36
[path] => node/%
[load_functions] => Array
(
[1] => node_load
)

[to_arg_functions] =>
[access_callback] => node_access
[access_arguments] => a:2:{i:0;s:4:"view";i:1;i:1;}
[page_callback] => node
[delivery_callback] =>
[fit] => 2
[number_parts] => 2
[context] => 0
[tab_parent] =>
[tab_root] => node/%
[title] => Work/Life Balance
[title_callback] => node_page_title
[title_arguments] => a:1:{i:0;i:1;}
[theme_callback] =>
[theme_arguments] => Array
(
)

[type] => 6
[description] =>
[position] =>
[weight] => 0
[include_file] =>
[href] => node/36
[tab_root_href] => node/36
[tab_parent_href] =>
[options] => Array
(
)

[access] => 1
[localized_options] => Array
(
)

[original_map] => Array
(
[0] => node
[1] => 36
)

[status] => 200
[extra_arguments] =>
)

[is_cacheable] => 1
[header_info] => Array
(
[status] => 200 OK
[status-number] => 200
[content-type] => text/html; charset=utf-8
[content-type-basic] => text/html
[charset] => utf-8
[headers_sent] =>
)

[matched_header_info] => Array
(
[enabled] => 1
[extension] => html
[lifetime_max] => 604800
[lifetime_min] => 21600
[comment_start] =>

-->
)

)

thanks for any help!

am logging in with Firefox.
am NOT logged into IE 8.
and, when i log OUT of FFox, i can successfully cache pages.
FFox, Opera, Safari and Chrome all cache pages for anon users.
IE 8 has stopped...
?

excellent. deleted ALL cookies just to be safe, and it's working again. thanks!
loving this module!!