Why is Photoshop suddenly slow when saving .bmp images?

[Guest]

I am using Operating System: Windows 7 64-bit Version: 6.1 Service Pack 1 and have Adobe Photoshop Version: 13.0.1 (13.0.1.3 20131024.r.342013/10/24:21:00:00) x64

Within the last few weeks I have noticed a considerable slow down when I am saving .bmp images.  .  It just took 33 seconds to save a 729x922
pixel 24bit bitmap that I had cropped.  It has never taken this long to save images in the past.  As far as I know nothing has changed within the computer.  I have checked for updates to Photoshop and it shows I have the latest updates installed.

Does anyone have a suggestion as to why it is suddenly taking so long to save?  And how I can fix it? 

The processor speed and memory are:

Processor speed: 2693 MHz

Built-in memory: 7759 MB

Free memory: 4914 MB

Memory available to Photoshop: 6842 MB

Memory used by Photoshop: 70 %

[Trevor.Dennis · Accepted solution]

If this is a new behaviour, then I'd be inclined to try resetting Preferences.

[Guest]

This definitely sped up the saving process.  Thank you!

[Guest]

Further to my initial question, I am noticing that saving the .bmp files are slower when I am removing the alpha channel from the 32 bit image to save it as a 24 bit image.  Why would it take longer to do this as I have already deleted the alpha channel?