I know this thread is old, and Revolution may fix this, but we're still using Evolution (1.0.2 & 1.0.5) and this fix worked for us. From what I've seen this is still an issue for lots of people. I hope this helps someone!
Firstly, I'm not a coder or programmer, so take the meaning of what I say, not necessarily the actual words.
Second, the noConflict fix posted by bunk58 did not work for us (thanks for the try though!). Regardless, after digging into the included jquery library from the nivo-slider download, it seems noConflict is already being called there (at least as of version 1.4.3, we didn't check the older versions), so that is moot.
Third, this assumes you have installed nivo-slider correctly! We did and yet it didn't work. This is what we figured out after LOTS of troubleshooting.
The Problem:
As I understand it, the problem we were having stemmed from a variable conflict.
Mootools (runs the menu in modx) started an instance of jquery for the menu, but when the slider code came in to do the same, it appeared to throw away part or all of the first instance of jquery (the one mootools was using), and created its own. We proved this to be the case by switching the two calls' locations in the html header so either one would call first or second and it proved to be true: whichever was called last (mootools for the menu, or the jquery file for nivo slider) was the one that worked, the other didn't.
Again, as I understand it, it turns out modx and nivo javascript uses a variable of "$" to refer to jquery in all their code. This same variable was being used each time jquery was called, regardless of source (mootools or nivo). Therefore, the variable was initialized for one of the functions (the last) but not both. So for example If mootools was called first, then nivo was after, nivo would be proccessed last and initialize the variable with the info it wanted, so when the page rendered nivo would get the info it was looking for, and mootools would not, so mootools would break and not work.
The Fix
Basically what we did was change the variable in the nivo slider specific *.js files (see attachments for an example) so the variable used on the nivo jquery call was some random variable (we used $jQ$), essentially allowing both calls of jquery to live on the same page, and able to find the info they each needed.
This may seem basic to any/all programmers/coders out there, but I'm not one of you, so sorry if this seems like an overly obvious solution.
Feel free to use the attached files for your install. If you have the same problem and nivo is installed correctly just replace the default ones you put in modx with these, and it should work. Make sure you replace the right files! MAKE LOTS OF BACKUPS BEFOREHAND.
As usual, I don't warranty these for any purpose, don't hold me responsible for anything if you use them, etc. etc. MAKE LOTS OF BACKUPS.
,Rooks
