I noticed in one of your screen shots in one of your threads that you have very little hard drive space left, something like 12 GB, and that is precariously little space to be shared by Photoshop's scratch disk and the swap files of the OS.

It's not surprising that large files cause you problems.

Somehow I'm pretty confident that I'm understanding you a lot better than you understand my post. 

I understand you are using an ME version of Photoshop, so you need to be able to write both from left to right and from right to left.  You seem to be having problems reversing direction from one of the menu items, and those problems arise when you work with very large files.

What I am telling you is that what may be precipitating those problems in large files is the very little hard drive space you have left in your one and only drive you have designated as your primary scratch disk, as evidenced by your screen shot:

Since that drive "OS X" appears to be also your boot drive, that means that the paltry 12 GB of HD space you have left on that drive will have to be shared by Photoshop's scratch disk with the swap files of the OS.  That is not enough, in my opinion.

I like to reserve a dedicated hard drive with 160 GB for Photoshop's scratch disk alone.

Hope I explained myself better this time.

I understand you don't think a 35 MB file is too large, but what I am telling you is that a 35 MB file can in fact precipitate your problem because you have inadequate resources.

Your available installed RAM is minimal.  And your available hard disk space on the boot volume you have designated as your only Photoshop scratch disk is indeed insufficient to accommodate both the swap files of the OS and Photoshop's scratch disk.

It looks like you've carved out tiny partitions of your hard disk for no apparent reason.  That is a very bad strategy.

With your setup, I would absolutely expect you would have all kinds of problems.  For sure.

If you have only one hard drive, you are forced to use that drive for scratch disk and for the OS.  Partitions do not help at all, as you still have a single read/write head on the whole hard drive.

So, with just the one drive, do not partition it at all.

Why limit the amount of available hard drive space that both the swap files of the OS and Photoshop's scratch disk can use.  Don't partition it!

Be aware that Photoshop may need a scratch disk up to 50 to 70 times or more the size of your largest file or more. 

The OS will also need to create swap files in that same space in order to work with your tiny amount of installed RAM.

So my advice:

1.-- Max your machine out with RAM, put in as much RAM as the machine will take.

2.-- Do not partition your boot drive at all.

3.-- Get a physically separate hard drive for Photoshop's scratch drive.  If you have a laptop that will not accommodate a second internal drive, then get an external FireWire hard drive.  You can partition that external drive, but dedicate one partition of at last 150 GB to be your primary Photoshop scratch disk drive.

Photoshop is very memory hungry, and the ME edition, with its bidirectional text, requires even more resources than the standard version.

Yes, adding another partition (your Files HDD) as secondary scratch drive will alleviate your current situation, if simply because you have an EXTREME shortage of available scratch disk space now.

But having no partitions whatsoever on the one and only drive in your laptop would be infinitely better.

You are very welcome, Mahmoud.  It was my privilege to try to help.