Not being an IE expert, I do recall there is a setting to dictate how often you use your browser's cached version.
If you go to Tools -> Internet Options -> then click on 'settings' next to 'Browsing History", what does it say for how often your computer checks for newer versions? Mine is set to 'automatically' and I don't have this problem. Maybe yours is set to 'never'?
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"Without the darkness, how would we see the light?" ~ Tuvok
Editor for Television Category