Jumpy Mouse with MDP(Thunderbolt) to DVI connector

Hi!

OK - I had my 2011 21.5" iMac now for a week. Loving it so far!!

BUT there is an issue - I am using my 23" Samsung monitor from my retired PC (Good riddance!!! ) as a secondary display via a MDP to DVI connector (the official white Apple one).

The funny thing is, when the MDP is plugged into the Thunderbolt port - it causes my mouse pointer to skip/jump EVERY 4 seconds. It is extremely bothersome, especially when trying to do precise graphical/photo work. I have tried all settings, other mice etc. The skipping/jumping happens when the 2ndary display is switched off, the jumpyness vanishes when the 2ndary display is switched on.

My test summary is as follows:

Case 1:

Second display switched off, but MDP to DVI connector connected to 2nd display.

Result 1:

Mouse skips/jumps every 4 seconds (testing just by moving the mouse cursor in a circle continuously)

Case 2:

Second display switched on and connected via MDP to DVI connector to iMac.

Result 2:

Mouse is silky smooth, absolutely NO skipping or jumping of the mouse cursor!

Case 3:

MDP to DVI connector unplugged from iMac.

Result 3:

Mouse is silky smooth, absolutely NO skipping or jumping of the mouse cursor!

THUS - the MDP to DVI connector causes the jumping/skipping of the mouse cursor when the MDP to DVI connector is connected, but the 2ndary display is not switched on.

Sometimes I only want to work on the iMac - without using the secondary display. I don't want to unplug and re-insert the MDP all the time. I got an iMac for trouble-free computing :-)

I see there this issue was previously also logged in the community and a patch fixed it. PLEASE Apple, can you release a patch for this re-occurring issue!

The archived thread is here:

https://discussions.apple.com/thread/1830794?answerId=8917257022#8917257022

Here is the quote:

"

Re: Mini DisplayPort to Dual-Link DVI Adapter creates jumpy mouse cursor

May 12, 2009 8:18 PM (in response to reportjeff)

The 10.5.7 update finally solved this issue for me.

I no longer see any dp events in the console and mouse movement is silky-smooth 100 % of the time - no more random jumps.

*crosses fingers* I hope I didn't speak up too soon 😉

MBP 2.8 (late 2008) "