PH using all of a core's CPU time until main window opened

[ecm]

I'm using PH 2.28 (r5073) on MSWindows XP SP3. Each time PH is started now, it reproducibly uses ca. 50% CPU time so that one core (of my dual core CPU) is fully utilised. This stops immediately after opening PH's main window. Using the PH tray icon's menu to view the properties of eg PH's own process does not make it stop.

I usually hibernate my system (and after being resumed like that, PH does not eat up CPU time like this) so PH isn't started often. I think that initially PH did not behave in this way though. I've been using it since 2012-09-06.

[dmex]

Do you have any screenshots?

[ecm]

Screenshots? Of the PH display after startup? I can make some after next reboot if you think you'll have any use for them.

[ecm]

Here's some screenshots. The first one (the smallest) shows just the tray shortly after starting PH. The second one shows the menu of PH's tray icons, the third, fourth, and fifth show the properties of PH's process at that time. The sixth, seventh, and eighth show PH's process's property "Performance" tab in the right part of the image, and the main PH window in the left part.