PyDev 1.5.3 & 1.5.7
Eclipse 3.5.2
Mac OX 10.6.3 (Snow Leopard)
Sometimes, but not always, a window flashes very briefly on the screen before the popup window with the docstring is displayed. If docstring popup is disabled, there is no flashing window. The window flashes so quickly, that I've been unable to determine content. The window flashes at different locations on the screen and is not constrained by the Eclipse window.
I have also seen this flash in a text file editor when hovering over a misspelled word, just before the popup saying that the word is misspelled.
In both cases, the flash doesn't happen every time you hover over the text.
No entries are recorded in the Eclipse Error Log when this happens.
I cannot reproduce the flashing with a similar setup (Eclipse 3.5.2 M20100211-1343 / Pydev 1.5.7) on Ubuntu 10.4, nor can I reproduce it on Eclipse 3.5.1 / Pydev on Mac Snow Leopard 10.6.3.