Binary package hint: rhythmbox
If I enable the "Portable Players - MTP" plugin, I see this in an strace, repeated thousands and thousands of times. The UI hangs until it decides it has had enough, then the plugin is "active". I have no idea if it actually works, as I don't own an MTP device.
This behaviour also happens when starting up Rhythmbox with the MTP plugin active. It takes tens of seconds to start up as a result.
gettimeofday({1195406122, 113969}, NULL) = 0
writev(17, [{"l\1\0\1\22\0\0\0\\f\0\0\247\0\0\0\1\1o\0*\0\0\0/org/fr"..., 184}, {"\r\0\0\0usb.vendor_id\0", 18}], 2) = 202
gettimeofday({1195406122, 114187}, NULL) = 0
poll([{fd=17, events=POLLIN, revents=POLLIN}], 1, 25000) = 1
read(17, "l\3\1\1[\0\0\0X\315\1\0]\0\0\0\6\1s\0\5\0\0\0:1.72\0\0"..., 2048) = 203
read(17, 0x8c9a9e0, 2048) = -1 EAGAIN (Resource temporarily unavailable)
Disabling the MTP plugin alleviates the problem.
ProblemType: Bug
Architecture: i386
Date: Sun Nov 18 17:15:52 2007
DistroRelease: Ubuntu 7.10
NonfreeKernelModules: vmnet vmblock vmmon fglrx
Package: rhythmbox 0.11.2-0ubuntu4
PackageArchitecture: i386
SourcePackage: rhythmbox
Uname: Linux flash 2.6.22-14-generic #1 SMP Sun Oct 14 23:05:12 GMT 2007 i686 GNU/Linux
Confirming i got the same results it hang for a while and then continue working. thanks for your report.