iOS4 ActiveSync patch?

Is anyone familiar with the issue posted at iOS 4: Exchange Mail, Contacts, or Calendars may not sync after update?

My company's Exchange hosting service broadcast a notice about this patch. I'm using a pwnagetool-JB'd iOS4 on a 3GS (old iboot, old bb, AT&T), and am wondering if it is safe to apply.

The service notice read as follows, if anyone is curious:

Quote:

Shortly after the release of Apple’s new iPhone 4, reports surfaced about poor ActiveSync performance. Apple has released a patch to correct this issue and we strongly encourage users to apply it. The patch applies to all iPhone 4 devices and iPhone 3G and 3GS devices updated with the iOS4 operating system software.

Failure to apply this patch may result in ActiveSync errors, including failure to synchronize e-mail, calendars, and contacts. Install instructions and additional information can be found on Apple’s support site, iOS 4: Exchange Mail, Contacts, or Calendars may not sync after update. A reboot of the device is required after installation and users may need to reconfigure ring tones and some personal settings.