I'm having very hit and miss results with dropping audio clips (wav files) onto the timeline.
 
Some clips show up on an audio track, where as other clips fail to appear (despite a "conversion" progress bar showing briefly).

Here is an example of a file that did show up

General
Complete name : C:\_U_SAMPLES\_LOOP LOFT\CompleteTakes_Vol1\84bpm_TribalFolk\Tracks\01_Kick.wav
Format : Wave
File size : 31.5 MiB
Duration : 3mn 48s
Overall bit rate mode : Constant
Overall bit rate : 1 155 Kbps
Producer : Logic Pro
Encoded date : 2012-04-25 16:20:53

Audio
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : 1
Duration : 3mn 48s
Bit rate mode : Constant
Bit rate : 1 152 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Stream size : 31.4 MiB (100%)

 
And here is an example of a file that didn't

General
Complete name : C:\_U_SAMPLES\_LOOP LOFT\CompleteTakes_Vol1\84bpm_TribalFolk\Tracks\02_Snare.wav
Format : Wave
File size : 29.8 MiB
Duration : 3mn 36s
Overall bit rate mode : Constant
Overall bit rate : 1 155 Kbps
Producer : Logic Pro
Encoded date : 2012-04-25 16:20:54

Audio
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : 1
Duration : 3mn 36s
Bit rate mode : Constant
Bit rate : 1 152 Kbps
Channel(s) : 1 channel
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Stream size : 29.7 MiB (100%)

 
As far as I can tell, the format is identical.
 
I just bought these professionally recorded files and they seem to be the most problematic, but they are not the only wave files that X3 won't accept.

I am running Sonar X3e (Build 244) x64 on Windows 7 ultimate Sp1 with a Behringer UFX 1204 interface (firewire) using ASIO.

Is it possible some are broadcast waves? If so they may be inserting far to the right on the timeline. Try toggling "Always Import Broadcast Waves At Their Timestamp" in Preferences > File > Audio Data

Turns out exactly the opposite was true.
I had that box checked already (must be the default), and when i unchecked the box, I seem to be getting reliable imports now.

Cheers.
 
 

Toggling the value just means changing the value from the current state. When enabled (the SONAR default), waves are placed on the timeline according the timestamp in the wave. When disabled, waves are placed on the timeline where they are dropped. The waves appear to be from the same source. One wonders why some files are broadcast waves and others are not.

I also had to uncheck that box when some .wav files I was sent ended up at something like measure 1200 after import. Couldn't find a reason for it and the .wav files imported as expected in other programs.

The reason is the timestamp in the files. Some programs will handle the timestamp differently possibly with an offset or even ignore it by default. By default SONAR places broadcast waves based on the timestamp on a timeline that starts at 0.

In that set of stems, the kick track seems to be missing the extra timing info.
When i import the set into reaper, the rest of them lock in just fine and then I always have to go an fix the playback rate for the kick track. I think it's a descrepency on the part of the sound library vendor.
 
In sonar, with that option enabled, it wasn't that the items showed up way up the timeline, they just did not show up on the timeline at all.