Okay, just a quick survey to try and get a handle on a problem.  I have a part (in this case sheet metal, but it's happened on non-sheetmetal parts as well), and I want to edit an existing sketch with my SW 2008 SP5 package.  A few times, not always, but a few times in trying to select a sketch constraint on the graphics screen, there's a dreaded pause in the software which I refer to as an "ohnosecond" (see definition below), and then Solidworks transports to another section of the galaxy.  Now, I've gotten to the point where I've figured out that if I select the line instead of the constraint symbol right next to it, then go to the feature manager window and select the constraint there, life is good.  I guess I am just wondering if anyone else has had this problem, in an effort to try and determine what to do to fix it as it is somewhat random.

The enclosed part file repeats this error on my computer.  I have a Dell T5400, Xeon 5420 processor, nVidia Quadro FX 1700 display card with approved driver for SW (7.15.11.6956), Vista 64 / 8Gb memory.  If anyone with a similar system has time, please open my part and try editing the "Tab2" sketch as shown on the JPEG file.  Let me know if you have any issues after selecting/deleting the perpendicular constraint in the graphics window.   I've had a lot of grief between this computer and Solidworks, any help is greatly appreciated.

"Ohnosecond"  - The time between pushing the button and realizing you really shouldn't have pushed it! (R. Schneider)