I just purchased a ME-25 today, and set it up with my computer. I've already played around with it a bit together with SonarLE. Having stumbled upon this post I got a few experiences I'd like to share:
To me, the drop-outs and latency problems sound just like typical
MME-32 driver issues. MME-32 are not made for real-time processing. I recommend using
ASIO drivers. I've had similar problems with my MOTU 828 mk3 and MME-32 in another software that didn't support ASIO. Getting it to work with MME-32 is not worth the hassle. Use ASIO drivers and ASIO software.
To witch to ASIO mode, go to Options -> Audio. Click the advanced tab, and select ASIO from the Driver Mode drop-down box. Then OK. This puts Sonar into ASIO mode. Note that you can not use you audio card / ME-25 in any other software. If you do, you'll probably get no sound, and a warning telling you it's in use if you're lucky.
At this point you should be able to use the ME-25, since at least on their webpage, BOSS state that the divers got ASIO support.
If they don't, and/or if you also would like to use the built-in sound on your computer, I recommend
ASIO4ALL. The ASIO4All enable low-latency ASIO for as good as all soundcards. It runs fine with the integrated SoundMAX HD in my HP laptop and it even runs with the ME-25. ASIO4All is ".. free for the end user." You can read more about it on their
product breif.
ASIO4ALL allows you to set several parameters that affect latency. Read a bit on the net and play around with them. If you get clikking and dropouts, you have probably pushed the latency a bit too far.
I myself had to set the ASIO-buffer to 96 samples for the ME-25, but the built-in SoundMAX went all the way down to 64 samples. If your sound card support
WaveRT, then you can probably push the delay latency even lower. Total system latency, when I use the input from ME-25 and the headphones on my laptop is 9.8 ms. Half is input, the other half output. You can also play around with the delay settings for the ME-25. These are found in windows' control panel.
Using this setup I have no problems both monitoring and recording using the ME-25. When I monitor through the laptop sound card, you of course need to enable monitor for the correct channel in Sonar. If you monitor though the ME-25, don't enable monitor. First, because you already have the guitar sound from the ME-25. Secondly because the 10 ms or so monitor delay makes it sound like someone shoved you and your guitar into a small drainage pipe.
With some software I have experienced that the graphics drivers can mess up my computer. Well other drivers too to be precise about it, but graphic drivers are a common problem. Normally this is caused by DPC latency issues in you computer. "
DPC Latency Checker" is a small piece of software that you can download and check the "timing health" of your computer. You can read more about it and download through the link above. One trick regarding graphic drivers are to disable Aero in windows.
I do hope this helps you out and give you some time to play around with the ME-25.