A week after launching with great fanfare its Apps Sync for Microsoft Outlook, Google has addressed a number of shortcomings with this plug-in.

In a blog posting Tuesday, Google listed some popular Outlook add-ons and features that remain off-limits to Apps, even with the new sync tool.

"Unfortunately, some plug-ins don't yet work with Google Apps Sync for Microsoft Outlook, and we wanted to take this opportunity to highlight a few of the more common ones: Microsoft Office Outlook Connector, Acrobat PDF Maker Toolbar, Outlook Change Notifier," reads the Google posting.

To continue using any of these plug-ins, users have to uninstall the Google sync tool.

In addition, Apps Sync for Outlook doesn't play well with programs that interact directly with the Outlook data file, such as Windows Desktop Search and PGP.com's encryption plug-in.

Specifically, Windows Desktop Search will not properly index Google Apps Sync data files. "So in order to stop indexing from running indefinitely, the Google Apps Sync installer disables it. We recommend using the default Outlook search," Google said.

Once again, to re-enable Windows Desktop Search for Outlook data files, users have to uninstall the Google sync tool, but there's a caveat: People using version 1.0.22.1945 or lower of the Google tool must first install the latest version and then uninstall it to re-enable indexing.

"We're working with Microsoft and other partners to help fix these issues and support additional Outlook features like multiple calendars. We'll keep you posted on our progress," Google's posting reads.

On Wednesday, Microsoft posted its own take on the Outlook search problem in an official blog, characterizing the issue as "a serious bug / flaw" in the Google tool.

"The installation of the Google Apps Sync plug-in disables Outlook's ability to search any and all of your Outlook data," reads the Microsoft post.

According to Microsoft, the problem is that the Google tool modifies a registry key that disables Windows Desktop Search's ability to index all Outlook data and make it searchable, not just the Outlook data that gets synchronized from Gmail.

"Because Outlook search relies upon the indexing performed by Windows Desktop Search, Outlook search functions are broken as a result," Microsoft said.

Contrary to Google's recommended remedy, Microsoft maintains that uninstalling the plug-in may not fix the issue and that the way to solve the problem is to change the registry key that was modified. Microsoft offers a step-by-step explanation of how to do this in its blog post.