Yes, I already have seen this little bug, but this is not a problem in my code but a problem with some mis-encoded bitmaps....
The problem is that Windows (XP up to Vista) doesn't support 32bits bitmaps, and they shift properly written bitmapts by 1px. Others applications and OS doesn't (try opening your images with Safari for Windows, you should not see the 1px-shiftage).
In a future version, I could give the possibility to read/write the bitmap in both formats. But because nobody has responded to my message, I've not worked on my plugin anymore because he worked well for my own use. If you are interested, I can publish another version in 1 or 2 weeks (now I've examens at school).
Fremy