Excel removes all data validation lists at the opening of the workbook

Hi guys,
this thing is driving me crazy; here is the thing: I have developed a quotation model in Excel, with data validation lists, a simple VBA macro and when i think everything's working out, i get a message at the opening of the workbook stating that Excel found some unreadable content and that it must repair/recover the unreadable content; when i click OK, the workbook opens and a message appears stating that Excel successfully repaired/recovered the file by removing some feature: "Removed Feature: Data validation from /xl/worksheets/sheet6.xml part". When i open the log file repairs, here is the log:

<?xml version="1.0" encoding="UTF-8" standalone="true"?>
-<recoveryLog xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"><logFileName>error064840_02.xml</logFileName><summary>Errors were detected in file 'C:\Users\Admin7\Documents\CommercialLighting\Jobs\Quotation - Park Regis - 18102012\Quotation_ParkRegis_Hotel - MASTER.xlsx'</summary>-<removedFeatures summary="Following is a list of removed features:"><removedFeature>Removed Feature: Data validation from /xl/worksheets/sheet6.xml part</removedFeature></removedFeatures></recoveryLog>

Bottom line: All the data validation lists get removed from the file and my model no longer is usable.

I have been looking for a solution everywhere and i haven't been able to find any to my problem. I am not sure what's wrong with my model: I thought the original model was corrupted so i created the same model in another workbook but it happened again. I thought it was the VBA code that screwed everything up (I create a data validation list in one cell, from a string of dynamically generated list of characters, which i thought may get too long. So i created another workbook without the VBA code and the same problem happened again); sometimes you can create a few data validation lists and the problem doesn't appear, but it seems like if many lists are applied to many cells, then the problem appears.

Anyway, i have no idea of how to work it out and i hope one of you guys may be able to help me out with this; that'd be awesome, you'd be awesome haha

I attach a workbook to this post, try to open it, you'll see my problem.

MANY THANKS.

PS: When opening this file, Excel will ask you if you want it to repair the file: If you don't, it doesn't even open it so pointless; if you do, it'll remove all the data validation lists and you won't know where they are. Basically they're supposed to be in the tab "LU_DET_BA", normally all the white cells in this tab are lists .... But then they get simply erased.