GuiTabBookProfile bitmap problems?

Here is the snippet from the defaultprofiles.cs

if( !isObject(GuiTabBookProfile) ) new GuiControlProfile (GuiTabBookProfile)
{
fillColor = "255 255 255";
fillColorHL = "64 150 150";
fillColorNA = "150 150 150";
fontColor = "0 0 0";
fontColorHL = "32 100 100";
fontColorNA = "0 0 0";
justify = "center";
bitmap = "./darkTab";
tabWidth = 64;
tabHeight = 24;
tabPosition = "Top";
tabRotation = "Horizontal";
tab = true;
cankeyfocus = true;
};

if( !isObject(GuiTabPageProfile) ) new GuiControlProfile (GuiTabPageProfile)
{
bitmap = "./darkTabPage";
tab = true;
};


However when I create a tab book in GUI, the bitmaps defined are never displayed on the tabs?

Help!

Thanks in advance!

Greg