How to set figure - caption spacing individually in a floatrow environment?

Question

In the preamble I use :

\usepackage[labelformat=empty]{caption}
\usepackage[heightadjust=all,floatrowsep=none,captionskip=3pt]{floatrow}

With this package I'm able to put two figures horizontally and vertically aligned besides one another, and refer to them individually. It also puts the captions at the desired distance (3pt) below the figure base. However, this applies to all such setups in the document.

Unfortunately things become messy, and the vertical spacing between the figures and their captions seem to vary randomly.

How can I fix that individually for some figure pair with the wrong caption spacing ?

Example :

\documentclass[pdftex,12pt,a4paper,english,dutch,leqno]{article}
\usepackage[top=1cm,right=1cm,bottom=1cm,left=1.5cm,noheadfoot]{geometry}
\usepackage{babel}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows,decorations.markings,patterns,calc}

\usepackage[labelformat=empty]{caption}
\usepackage[heightadjust=all,floatrowsep=none,captionskip=3pt]{floatrow}

\begin{document}

\begin{figure}[h!]
\begin{floatrow}
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm] (0,0) circle (3);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 1.}\label{fig:1}}
\hspace{1cm}
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm,rotate=45] (0,0) rectangle (2,2);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 2.}\label{fig:2}}
\end{floatrow}
\end{figure}

\end{document}

The floatrow package manual is mostly gibberish to me, and lacks examples.

Answer 1

Although the question includes an example code, there's no mention about the desired caption placement. The following example code contains the original layout and the one obtained by using \CenterFloatBoxes:

\documentclass[pdftex,12pt,a4paper,english,dutch,leqno]{article}
\usepackage[top=1cm,right=1cm,bottom=1cm,left=1.5cm,noheadfoot]{geometry}
\usepackage{babel}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows,decorations.markings,patterns,calc}

\usepackage[labelformat=empty]{caption}
\usepackage[heightadjust=all,floatrowsep=none,captionskip=3pt]{floatrow}

\begin{document}

\begin{figure}[h!]
\begin{floatrow}
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm] (0,0) circle (3);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 1.}\label{fig:1}}%
\hspace{1cm}%
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm,rotate=45] (0,0) rectangle (2,2);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 2.}\label{fig:2}}
\end{floatrow}
\end{figure}

\begin{figure}[h!]
\begin{floatrow}
\CenterFloatBoxes
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm] (0,0) circle (3);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 1.}\label{fig:1}}%
\hspace{1cm}%
\ffigbox[\FBwidth]
{\begin{tikzpicture}[>=stealth']
\draw[line width=1mm,rotate=45] (0,0) rectangle (2,2);
\end{tikzpicture}}
{\caption{\footnotesize\bf Figure 2.}\label{fig:2}}
\end{floatrow}
\end{figure}

\end{document}

As a side note, it's not clear why you manually change the caption layout inside the \caption command (this is not a good idea) instead of using \captionsetup.