Macbook Pro charging iphone but not detecting it

I'm having a reccuring problem with my Macbook Pro detecting my iPhone4. Some details:

-Running 10.7.4

-The phone is charging but does not show up in iTunes, iPhoto, or in /volumes.

-I've tried different USB cables.

-I'ved tried different USB ports

-All software is up to date

I've had this problem before recently and deleted itunes/iphoto preferences, reinstalled itunes, rebooted the phone, and rebooted the computer when previously having this problem and it was resolved for a short time but showed up again. I tried this same order of operations a second time and did not have luck. So after searching some forums I did the following steps in addition to the previous steps, I trashed AppleMobileDevice.kext file located in /system/library/extensions, I trashed MobileDevice.framework file located in /system/library/framework. There was one recommended file to delete that did not exist on my computer: /system/library/launchdaemons and locate the file com.apple.usbmuxd.plist-orig, granted the instructions I was following was for Mac OSX v10.6, so there is the possibility it may not exist anymore.

Any help or assistance would be great. I believe it is a software issue and not a hardware issue based on the fact the issues have been resolved a couple of times by trying a shotgun approach to the issue, although I don't know what has actually resolved the problem. I also feel it's a software issue with the computer and not the phone, although I could very well be wrong. That said, I am no longer having success in resolving the issue and it's quite frustrating.