I finally fixed my problem with Gnus. I'm writing this, hoping that it'll maybe help someone out there with the same issue.

The symptom: Gnus checks your IMAP mailboxes forever. The problem I had was with one of my mailbox names: I had a ampersand (&) in there, which had Gnus hanging forever trying to escape it. At least that's what looking at *imap-log* suggested. Activating the logging is as simple as executing (setq imap-log t).

The fix: Change your mailbox's name to something without & and update the .newsrc.eld accordingly. And wait for a proper fix. I'm submitting a bug report now.

Update: I found out that setting the label for your USB device is the less painful way to do this, see below.

The naming of my USB hard disks in Ubuntu differed from time to time, which became more and more annoying recently. When I booted up the system with my external hard disk attached, the disk would be mounted as /media/sdb6. However, when I plugged the disk in when the system was already up and I was logged in, it would mount as /media/usbdisk. This was very nasty, as it broke links and libraries of applications like F-Spot and Quod Libet.

The cure for this problem was to have proper /etc/fstab entries for these devices. I found out about udev, which is the device manager for Linux since 2.16: udev manages the device nodes in /dev. In addition to the usual names like /dev/sdb, udev in Edgy is configured to also create symbolic links that will never change their name, like /dev/disk/by-id/usb-WD_3200JB_External_574D414D5231343637323730-part5 or /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0. (/etc/udev/rules.d/65-persistent-storage.rules does this.)

Knowing this, I went and put the right paths into /etc/fstab. The following is an excerpt from my configuration. I have an external WD hard disk with two partitions, one vfat and the other ext3. The last entry mounts a SanDisk USB stick, which uses vfat again:

# USB WD
/dev/disk/by-id/usb-WD_3200JB_External_574D414D5231343637323730-part5 /media/WD_3200JB-part5 ext3 auto,users,defaults 0 0
/dev/disk/by-id/usb-WD_3200JB_External_574D414D5231343637323730-part6 /media/WD_3200JB-part6 vfat rw,nosuid,nodev,quiet,shortname=mixed,auto,users,iocharset=utf8 0 0

# SanDisk
/dev/disk/by-id/usb-SanDisk_U3_Cruzer_Micro_0000060326115761-part1 /media/SanDisk_Cruzer vfat rw,nosuid,nodev,quiet,shortname=mixed,auto,users,iocharset=utf8 0 0

The Gnome Disk Mounter, which I don't use, seems quite confused by this. However, the disks are now automatically mounted with nice names, and I can reliably link into my external disks.

Update: I found out that setting the label for your USB device is the less painful way to do this. E.g. after renaming your FAT32 device to MYDATA, Ubuntu will mount your device at /media/MYDATA. This page explains how to rename your device for all kinds of filesystem types: https://help.ubuntu.com/community/RenameUSBDrive

A feature that I missed in Metacity (the default Window Manager of GNOME nowadays) since my old FVWM days is focus follows mouse. This is easily configured in Metacity as I found out today:

gconf-editor /apps/metacity/general/focus_mode

Set this to sloppy and your windows are focused whenever your mouse enters them.

While you're at it, you might want to also check auto_raise and set auto_raise_delay to 0, so that the focused windows raise to the front.

Update: Jasper just tells me that you can configure the same by going to System -> Preferences -> Windows in the Gnome menu.