LS Retail 6.4 W1 POS application error in Windows 7

Dear Friends,

Right now I am using LS Retail 6.4 W1 based on Dynamics NAV 2009 R2. While using the POS I am facing an unique problem which appears only in Windows 7 PCs and not in Windows xp. If we copy any value from any other source (Excel, notepad or From any form (say Retail Item Card) of another NAV application) and paste in POS input area and press enter, the POS becomes non-responsive and unless i log off from POS and log in again, POS does not behave normally as usual. I dont think that the issue is coming because of special character paste. The client uses multiple applications at POS and they frequently copy and paste values from other applications to POS. If any of you have faced this issue and resolved it, please let me know.

Thanks in advance.

On further analysis, we found that the issue is emerging due to use of Alt+Tab short cut key to switch from any other application window to POS. The probable reason, when we are switching to POS, Alt key is activating NAV menu bar and if we press Alt key again before pasting the value, it works fine.