Excel 2010 strange issue: Clipboard memory automatically removed upon opening a new workbook

I observed a strange behavior of MS Excel 2010 (in Windows 7 platform) while I perform the following sequence of operations:

- Copy a range of cells from an excel workbook (Ctrl + C)

- Open a new workbook in the same excel session (Ctrl + N)

- Paste the clipboard memory into this new file (Ctrl + V)

Result: Ctrl + V doesn't paste the data; since, doing Ctrl + N seems to remove memory from the clipboard.

Has anyone come across this kind of problem before? If so, what is the workaround and the potential reason behind that? Thanks.

NB: I would presume this might perhaps be due to some add-ins. But, please note, I have never had this problem before and only started to appear suddenly (and, no add-ins were installed or no major stuffs were changed between those two phases).

Note that I have fixed the problem of clipboard memory loss. The source of this was a customized add-ins removal of which fixes the problem now.