If ad blocking causes the prob then may be you need to configure flash blocking
To enable or disable Flash blocking
Open Norton Personal Firewall.
In the Security Center, click Options > Internet Security.
On the Web Content tab, click the Global Settings tab.
In the list of Web sites, do one of the following:
To change Flash settings for all sites, click (Defaults).
To change Flash settings for a site in the list, click the site's name.
To change Flash settings for a site not in the list, click Add Site, then in the New Site/Domain dialog box, type the site's address.
In the Flash animation section, select one of the following:
Block
Permit
Click OK.
you may have it set to block