DMG files appear with .DAT extension

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DMG files appear with .DAT extension

When I download DMG files, they appear with the Graphicconverter icon (not much problem) and an additional extension: .DAT. (Big Problem). For example, they might be named newapp.dmg.dat. I have to manually delete the .DAT extension, to get them to mount. This started within the last month. Two things I know that may be relevant: my son installed Skype, and I updated to the latest GraphicConverter. (Universal, 6.5.1.) I have the latest software updates. I have repaired permissions, run DiskWarrior, and run Onyx to reset the Launch Services and do periodic maintenance. I also rebuilt the Spotlight index. I have searched all over but can't find the solution. As an aside, I've noticed that various .DAT files (legit) on my system now have the GraphicConverter icon and the Get info says they are to open with GraphicConverter (not right). Any ideas? This is happening on a Powerbook 15 inch OS 10.4.11. (powerpc) and not the PowerMac. But, I haven't updated GraphicConverter on that machine. I have a feeling the issue began before we downloaded GC, come to think of it. Sorry so long.

PowerMac G4 MDD Dual 1.25, Mac OS X (10.4.11), 2G ram; original Superdrive; Apple Computers since 1988

Posted on Sep 20, 2009 1:46 PM

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Answer 1

BDAqua

Level 10

250,259 points

Sep 20, 2009 2:24 PM in response to Picky

Where are these being downloaded from, could it be from a PC or FAT32 Drive?

Does a DMG from here do the same thing?

http://www.apple.com/support/downloads/

The set to open with GC is a different problem I think, likely that the new version knows .dat files from WinMail is my guess.

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Answer 2

Picky Author

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Sep 22, 2009 11:39 PM in response to BDAqua

These were applications downloaded from internet reputable sites. For specific examples, the OpenXMLConverter for Office 2004 (for Mac) from Microsoft, and Xbench (a benchmarking app.). I downloaded directly from the developer's sites. No PC or Fat32 drive was involved. Their disk image files downloaded with ".dat" appended to the name. Both apps worked great once I removed the .dat extensions.

I did try a download from the Apple Support Downloads page. The IpodResetUtility dmg file came in the same way, with ".dat" on the end. Not every download does this: if they come in as a pkg file or a zip file it doesn't happen.

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Answer 3

BDAqua

Level 10

250,259 points

Sep 23, 2009 3:32 PM in response to Picky

Wild guess here, do you have any 3rd party APPs that could affect this?

Stuffit AVR? Speed Download, etc.?

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Answer 4

Picky Author

Level 1

25 points

Sep 28, 2009 12:37 AM in response to BDAqua

Looked for (and read about) Stuffit AVR, don't think I ever had it. I have the latest Stuffit Expander now.
Never did install any "download enhancer software."
Thanks for brainstorming.

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Answer 5

BDAqua

Level 10

250,259 points

Sep 28, 2009 1:17 AM in response to Picky

I hate behoovement worse than confusement! 😉

After much investigation, mulling, and psychic reverse engineering, here's what I'd try...

Safe Boot , (holding Shift key down at bootup), it will try to repair your Disk Directory while the spinning radian is happening, so let it go, & use Disk Utility from there to Repair Permissions...

Reset Launch Services...

http://www.thexlab.com/faqs/resetlaunchservices.html

Then reboot.

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Answer 6

Picky Author

Level 1

25 points

Nov 30, 2009 8:15 PM in response to BDAqua

We did rebuild the Disk Directory and we Reset the Launch services; still had those durned .dat extensions. One of those things, I guess. Anyway, just to finish this one off, it's now a moot point as the owner of the PowerPC PowerBook in question has since bought a new MacBook Pro (Not because of this problem!).

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Answer 7

BDAqua

Level 10

250,259 points

Nov 30, 2009 8:46 PM in response to Picky

Thanks for the report, sorry we couldn't figure it out though! 🙂

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