Hi Tim,
i've got a problem with gui objects in devel_0_37. when i move the mouse across some of the gui objects (sliders, grid ...) i can hear some clicks ... pd runs in realtime mode, i reniced pd-gui to 19, but still i hear some clicks...
Seems like you are doing the right things: lite-duty window manager [you are using windowmaker, correct?], -rt flag, etc.
I don't have any such problems, and I am using Pd version 0.37.1 devel with Fluxbox windowmanager under Gentoo on a laptop. I do notice that if I have another app running that does something with the screen space [the animations played in the Gkrellm2 system monitor, for example], then I get periodic interruptions of sound. However, I can use grids, sliders, and even open up subpatches and drag them around without fear of boo-boos.
So what is the differences between my system and yours? It could have something to do with PCI interrupts, I suppose. Where is your sound card and where is your video card in regards to IRQ assignments? Are you on a desktop or a laptop? What is your sound card and what is your video card? Can you reassign IRQs in the BIOS, or failing that, try the card-rearrangement-voodoo-dance? Low-latency and/or preemptive kernel patches? Kernel version? Need...more...information.... ;-)
best, D.