Make an openOffice spreadsheet with clipman running. Copy a formula to a range of cells. (ie. define A1 as 1, B1 as =A1+1 and then Ctrl+C on B1 and select a range Shift-Arrow keys and Ctrl+V). When you paste, you expect the pasted items to contain formulas (e.g =G1+1), but if you take too long, you get lots of 1's. There is a similar misbehaviour when selecting or copying text in OpenOffice writer with an in-line graphic. Clipman should recognise that the clipboard selection cannot be accommodated on the X selection, and should either convert it (without postive feedback), or ignore it entirely.
If you are running Xfce 4.8, the clipboard manager is built into xfsettingsd, which for a start used the manager written in the clipman plugin on top of gtkclipboard. The manager in 4.8 has been reverted to the gsd clipboard manager which uses pure X11 code, please simply upgrade to latest xfce4-settings 4.8.2 to fix these copy/paste issues. *** This bug has been marked as a duplicate of bug 7588 ***