Filter graph: column's widths change if filter box ticked

Hello,
In TortoiseHg version 1.9.2+57-91df37182065 on Windows XP SP3,
I use "Filter graph with revision sets or branches" and I changed the width of a column (i.e. Rev column in the enclosed "before filter" picture).
Then, when I tick the filter box, the widths of the columns come back to their initial values. See “after filter” picture enclosed.
It's a little bit annoying.
Best regards,
Arnaud