ITunes 10 does not detect my iPhone

Question

i recently upgraded to itunes 10, and i have a 1st gen iphone. after upgrading, i synced my iphone and everything went fine. soon after that, i had a totally unrelated hard disk drive failure. luckily all my data were backed up, apple replaced my hard disk, and i restored all my data. however, when i tried to connect my iphone to itunes to sync, itunes would not detect the iphone. i tried many fixes, the only one that worked was to reinstall itunes 10 (which is a pain, because you have to get rid of lots of files.) last night, after reinstalling itunes 10, i connected my iphone and itunes detected it and synced. i thought the issue was solved for good and maybe was related to the restoring of the backed up data. however, i just tried to sync again, but the problem has re-appeared. my itunes does not detect my iphone.
the console message i get is as follows:
9/7/10 3:56:17 PM usbmuxd[30] connect_toport (thread 0x100581000): Could not connect to USB mux port 32498 for device 2: Connection refused
9/7/10 3:56:17 PM usbmuxd[30] MobileDeviceConnectlocked (thread 0x100581000): Could not connect to lockdown port on device bac8e3086978950d97c077103aa8996ccb56eec1.
9/7/10 3:56:17 PM usbmuxd[30] _MobileDevicePairWorker (thread 0x100581000): Pair worker (0x0x100581000) could not connect to lockdownd: kAMDMuxConnectError
i thought that usbmuxd is built for linux, but is it doing in itunes 10? but it must belong to it, because i also got this (i think when booting, but i am not sure):
9/7/10 3:33:40 PM com.apple.usbmuxd[30] usbmuxd-201 built for iTunesTen on Aug 12 2010 at 17:33:03, running 64 bit
what is going on? i don't want to reinstall the **** itunes every time i have to sync. any solution? thanks

Answer 1

Here is the diagnostics test ran within iTunes (under help tap inside iTunes).
Microsoft Windows XP Professional Service Pack 3 (Build 2600)
Dell Computer Corporation Dimension 3000
iTunes 10.0.0.68
QuickTime 7.6.7
FairPlay 1.9.16
Apple Application Support 1.3.2
iPod Updater Library 10.0d2
CD Driver 2.2.0.1
CD Driver DLL 2.1.1.1
Apple Mobile Device 3.2.0.47
Apple Mobile Device Driver 1.49.0.0
Bonjour 2.0.3.0
Gracenote SDK 1.7.1.420
Gracenote MusicID 1.7.1.78
Gracenote Submit 1.7.1.106
iTunes Serial Number BXXXXXXXXXX
Current user is an administrator.
The current local date and time is 2010-09-17 01:08:36.
iTunes is not running in safe mode.
WebKit accelerated compositing is disabled.
HDCP is not supported.
Video Display Information
Intel(R) 82865G Graphics Controller
** External Plug-ins Information **
No external plug-ins installed.
iPodService 10.0.0.68 is currently running.
iTunesHelper 10.0.0.68 is currently running.
Apple Mobile Device service 3.2.0.0 is currently running.
** Device Sync Tests **
*No iPod, iPhone, or iPad found.*
Please help!!!!!!