828 Mk3 and Ultralite Mk3 daisy chained (sync problems)

[mixfix]

Hi all.
I am new to this forum and I was wondering if anyone could help me with my issue.

As I said above I own a 828Mk3 and a Ultralite Mk3 daisy chained in Windows Xp sp2. Both work really well but sometimes (not all the time) the ultralite comes out of sync and starts to "sqeeeel" a high note causing the daw (presonus studio one pro) to stop recording.
i use both to connect my hardware devices into my recordings and mixes. Somedays everything is great other days it's hell...

I have the latest drivers but I have not updated the firmware of my 828 MK3. Should I do that? Why is there an firmware update anyway+

I always promised myself not to do the firmware update because i heard many bad stories from other when updating...
But i am guessing thats not where my problem is? is it?

What could be the problem?

Many thanks in advance for taking time to answer my questions.