>> Yes, it appears that under certain (as of yet unknown) >> conditions the while loop at line 2264 will never exit. The loop >> control looks like this: >> while ( v <= ceData.maxSteps + 1 ) { I found the issue. The slider drawing code did not initialise the min/max variables, therefore anytime a slider was shown there was a risk of a random application hang. This has been fixed in GIT hashes 6c72a84 and 2c0153b (Qt3 and TQt3, respectively). Thank you for your help with this issue; the backtraces were invaluable in tracing the problem! Tim