tabbar plugin: not enough room error

Hi,
I'm using the TabBar plugin on Ubuntu with gVim to display the buffer list.

Sometimes when I open a new buffer from the project.vim window I get this error:

Error detected while processing function
<SNR>50_Tb_AutoUpdt..<SNR>50_Tb_Start..<SNR>50_Win_FindOrCreate:
line 47:
E36: Not enough room
file: system/application/controllers/admin/home.php, cwd:
/home/carlo/workspace/ferro, lines: 56

I don't think it is related to the project.vim plugin and I think that
this error may appear without using project.vim too, but I've never
tried.

After I get the error it opens the new buffer in the tabbar buffer
list and it is a total mess.

Any idea?