Obnoxious old Epson Scan bug: EPSON Scan cannot be started

I've just installed an Epson Perfection V700 scanner with Epson Scan software dated Jan 2008.

It has the same bug referenced on Macintouch 3 years ago:

Macintouch - Multifunction Peripherals: Epson

Feb. 16, 2005, Julian Hearne
... the Epson Scan software for the CX5400 is not compatible with OS 10.3.7’s Fast User Switching! It works fine in an Admin account, but if you switch to another user account it creates an error message dialog box in the middle of the users desktop stating “EPSON Scan cannot be started . ---”. You can dismiss the message but each time you switch to another users account, except Admin, the message reappears...
Epson Tech Support says it’s a known issue and kind of blamed it on OS X...

Dave Robertson
I have reported a similar problem [as Julian Hearne] to Epson Support. Using Fast User Switching on an eMac (10.3.x) with an Epson CX5300 results in the continual appearance of a dialog saying "EPSON Scan cannot be started."

The dialog cannot be dismissed or clicked on in any way and it floats above all other applications. The only way to clear it is to run the "Activity Monitor" application and quit the "Twainbridge" process.

I found a 2004 Epson document saying Epson Scan is not compatible with Fast User Switching.

Happily a single chance hit gave me the clue -- the real problem is Epson Scanner Monitor and Fast-User Switching. That led me to a post by some obscure geek quoting Macintouch:

... Someone on August 10 mentioned that they were having problems with the Epson Scanner software on their G5. I had this issue as well; however, I removed the Epson Scanner Monitor startup item from my login profile.

This is used to allow the user to press the hotkey buttons on the Epson scanner; however, it's not necessary to use the scanner. Anytime I want to do a scan, I either open up the Epson scan software (which should be possible through Photoshop as well) manually then do my scanning. No more monitoring software eating up CPU cycles...

Oh ... wait, the above Macintouch quote is from a post I wrote in 2005.

Sigh.

Well, this time I couldn't find Epson Scanner Monitor in any of my Login Items [1]. It was running though, I could find the process with Activity Monitor.

I killed the process and deleted Epson Scanner Monitor.

The problem appears to have gone away.

So now the front button scan doesn't work, but that's no big deal. I never use those buttons anyway, this is a photo scanner not a document scanner.

So now the mystery is how Epson can manage to be so #$$@ $%%!@% incompetent? (Alas, the answer is that they don't have to be really competent, they only need be better than Canon.)

See also a 2004 post of mine on why device drivers suck.

[1] There's a design flaw in 10.4. Non-admin users can't see their Login Items, but admin users can't see other user Login items either.

Update 2/24/2008: Ok, Epson is only #$$@$ incompetent -- because Apple is even more incompetent. Last time I looked Apple made the iPod, OS X and the iMac, but if you use 'Fast User Switching' with an attached iPod you end up with a "this iPod is corrupted" message. I suspect either Apple fundamentally messed up Fast User Switching with 10.4 or they just don't care.

Epson still rates as "#$$@$ incompetent" because there are so many easy things they could have done besides trying to work around Apple's bad design. Here are 3 of them, it's easy to imagine more:

1. Document the problem and the fix in online FAQ and a readme file.
2. Detect Fast User Switching, deactivate Espon Scanner Monitor and inform the user.
   
3. Provide an easy way to uninstall or deactivate Epson Scanner Monitor...

Hmm. Maybe malevolent as well as incompetent ...