Files become corrupt

Question

Windows 7 64-bit
8GB Ram
Indesign CS5.5 with all updates
FIles:
small 20,000 word book (1 single document) with no pictures, from a Word file
500 page book (1 single document), with 20 small jpgs (about 2MB total), text generated from scans/OCR, inserted as unformatted text
various copies, new/moved, new/IDML, etc. generated as tests
Problems
Several (all?) files created since 05/05 (the initial manifestation occurred almost instantly) have become corrupted. It either shows up immediately or takes around 6-8 hours
Things generally done with a mouse (click and drag to make a text box, resize a text box, copy or move text, placing the cursor to edit) become sluggish (reszing a text box could take 5 seconds to 17 minutes), jerky or sticky (click and drag a handle, release it, the frame edge might move (if and when it does) 0.125" or 6"
clicking and dragging text sometimes moves the wrong text or releases it in the wrong place
New text boxes have multiple columns although the columns setting is 1
Doing some things (e.g. click on export) cause InDesign to freeze
Failed solutions
The suddenness of the problem made me think it could be a virus--tested the Word file (noted above) and my system:  found no malware of any sort
Changed the mouse: touchpad, Wacom Intuos, Logitech trackball (the Wacom tablet works 100% perfectly in Photoshop 32bit, but work only like a mouse in Photoshop 64bit--32/64 bit; drivers are current)
any attempt to go into InDesign security (as directed by a technician) fail: no permissions (my account has full administrate rights; a new admin account has full administrative rights) so whatever we could have done there, cannot be done
Exported the file as an InDesign Markup IDML, opened in InDesign
Moved content of file to new file
Creating a new file by moving or opening IDML, may not work at all, or will appear to work but the corruption re-occurs in 1-8 hours
uninstalled and re-installed InDesign
I uploaded a file to technical support. They promised to call back three different time. They did not. When I have called, they say, "24-48 hours they will call back." 
Thank you for any help you can give.

Answer 1

OK, so, I finally got a chance to read this through this thread. Can you post a link to one of the problem documents, or email one to me?
(Sorry, I had thought you had done so earlier, but I realized I just misinterpretted something you said).
Another thing to try, of course, is testing against CS6 (8.0.0.370). CS6 does fix a number of bugs and it's where engineers do development, so it's most likely to get easily fixed in CS6 before CS5.5, and there's a not-insignificant chance that CS6 fixes your problem already.
I think your best bet at this point is to try to isolate the problem and determine what about your documents causes this problem. While getting a new version of InDesign out that fixes your problem is not going to happen quickly (if at all), figuring out how to avoid the problem certainly is doable. After all thousands of people use ID every day and don't see this.
The best start is to get a minimal document that exhibits the problems (as few pages as possible). Once there, exporting it to IDML and opening the IDML in ID to confirm the corruption survives the IDML. If that's the case, then you can unzip the IDML and inspect it (it is human-readable XML) and try to determine what is unique/special about your document.
This might be a long odyssey. Of course, my experience is that putting in the effort is more likely to get you results than letting Adobe Support do it for you, but you might have a different scenario.
I don't want to make excuses for them, but I suspect what's going on is that the support people you are talking to are waiting for the higher-level support people, or even for Engineering, and they don't have good control over the timliness of those other people. But that's not an excuse for giving you callback estimates that are not met -- Adobe seems to have a serious problem with this and I would not give them a free pass for it. It seems to happen all too often.
If you totally get stuck you could try asking for the Noida Duty Manager and see what that gets you (Noida, UP, India is the location of Adobe's support center).
But realistically, I'm not sure that is going to make engineering work any faster. Maybe it'll just make them give you more realistic estimates for calls-back...