The LFG button is missing, and the system button is opening the LFG options.

Clicking on the computer icon (which should bring up the system menu) opens the LFG window, and mousing over it gives the LFG tooltip. Clicking the question mark brings up the customer service screen.

To verify this is an issue with Bartender, I selected only Bartender in the addons list at the character select screen. I also tested by exiting the game, deleting the Bartender settings file from WTF, and reloading. The bar positions reset to default, but the buttons were still wrong.

Disabling Bartender restores the micro menu to normal. This is tested in BCC - I don't have an issue on my retail build, and I didn't test this in Classic.

Screenshot of TOC to confirm version:

It's worth noting that commit 707195a already fixes this. I tried manually putting the change into my local copy, and the micro menu now works as expected. :) So I'm guessing you just need to repackage and release.

Correction, that commit fixes it for TBC Classic, but bugs it out for Vanilla:

Note the gap in the micro menu, and the bag bar is shifted over to the right and overlaps the dragon bars.

This might be a Blizzard issue. Tried this on vanilla with no addons enabled:

/dump MICRO_BUTTONS
Dump: MICRO_BUTTONS
MICRO_BUTTONS={
  [1]="CharacterMicroButton",
  [2]="SpellbookMicroButton",
  [3]="TalentMicroButton",
  [4]="QuestLogMicroButton",
  [5]="SocialsMicroButton",
  [6]="WorldMapMicroButton",
  [7]="LFGMicroButton",
  [8]="MainMenuMicroButton",
  [9]="HelpMicroButton"
}