My MacBook Pro be ballin' - beachballin' that is. Big freeze problems.

Hi,

My MacBook Pro has decided to start freezing up and beachballing whenever I use Skype, Mail, Plex and sometimes when I use Launchbar. Usually my MacBook locks up for anything from several seconds to a few minutes, making it nearly impossible to get even basic things done. Typically, whenever I load up or type something into the above apps is when it locks up. Mail just locks up whenever I do anything when it's in the foreground. If I leave these apps open, the freezing spreads to other apps I regularly use, such as Safari, or even Activity Monitor or the Force Quit Window when I'm trying to diagnose the problem and quit the problem apps.
It's happened to me a couple of times before over the past year, and I thought I'd fixed it by deleting then reinstalling Skype and Growl (which was also slowing things down a lot) using AppZapper. But that hasn't helped much this time.
It was getting so bad that I tried deleting all my plist files in ~/Library/Preferences, in the hope it was a corrupt plist file. But the same apps cause the same slowdown after having done that, too. Actually, Skype and Launchbar seem a little bit better now. Skype hangs now after I press enter to send a message in Skype. Actually typing is (sometimes, but not always) OK. Launchbar only hangs for a few seconds, and not all the time now. Mail is still awful.
Looking in Console, which I'm not very familiar with, brings up some recurring messages that don't look good:

(I'm not sure if this one is relevant, but it keeps appearing every few seconds)

18/09/2010 14:20:44 com.apple.launchd[1] (com.jft.PdaNetMac[13262]) posix_spawnp("/Applications/PdaNetMac.app/Contents/MacOS/PdaNetMac", ...): No such file or directory
18/09/2010 14:20:44 com.apple.launchd[1] (com.jft.PdaNetMac[13262]) Exited with exit code: 1
18/09/2010 14:20:44 com.apple.launchd[1] (com.jft.PdaNetMac) Throttling respawn: Will start in 10 seconds
18/09/2010 14:20:50 org.apache.httpd[13263] (2)No such file or directory: httpd: could not open error log file /private/var/log/apache2/error_log.
18/09/2010 14:20:50 org.apache.httpd[13263] Unable to open logs

The weird thing is I deleted pdanet ages ago. And searching in Launchbar, Spotlight and Houdahspot shows no relevant pdanet files other than my web receipt for buying it. The above error message keeps repeating ad infinitum.

I suspect these errors have more to do with the problem:

18/09/2010 15:17:27 Skype[14047] Error loading /Library/QuickTime/DigitalVoodoo.component/Contents/MacOS/Voodoo SDDV10: dlopen(/Library/QuickTime/DigitalVoodoo.component/Contents/MacOS/Voodoo SDDV10, 262): Library not loaded: /Library/Frameworks/DigitalVoodooLib.framework/Versions/A/DigitalVoodooLib
Referenced from: /Library/QuickTime/DigitalVoodoo.component/Contents/MacOS/Voodoo SDDV10
Reason: image not found

18/09/2010 15:17:31 Skype[14047] AppDelegate::checkAppFirstRun: error on NSPropertyListSerialization of old_plist: stream had too few bytes

18/09/2010 15:17:51 Skype[14047] Failure with ATSFontGetUnicodeCharacterCoverage(). Disabling font fallback optimization for characters not renderable.

These errors keep repeating as long as I have Skype open.

This message kept repeating when I opened Mail just now:

18/09/2010 15:50:30 Mail[14568] Failure with ATSFontGetUnicodeCharacterCoverage(). Disabling font fallback optimization for characters not renderable.

So perhaps this is a font problem? Does anyone know how to fix this? Any help appreciated. I rely a lot on my MacBook for my work, so the faster I can fix this without having to erase and install, the better. But I'll suck it up and reinstall if that's the only solution.

Thanks in advance! (^_^)