1Password crashing on Win 7

Just installed 1Password as a trial. Occasionally it crashes on win7, locks up the PC for a few seconds. It will restart OK. Can't see anything in the latest betas to resolve this. The event log shows (this probably won't help :-)):

Faulting application name: Agile1pAgent.exe, version: 4.1.0.538, time stamp: 0x54c643cb Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000 Exception code: 0xc0000005 Fault offset: 0x040cfeec Faulting process id: 0x1334 Faulting application start time: 0x01d04ad9178b9146 Faulting application path: C:\Program Files\1Password 4\Agile1pAgent.exe Faulting module path: unknown Report Id: 80af2786-b749-11e4-af31-2c27d7202687

and

Fault bucket,type 0 Event Name: BEX Response: Not available Cab Id: 0 Problem signature: P1: Agile1pAgent.exe P2: 4.1.0.538 P3: 54c643cb P4: StackHash_3876 P5: 0.0.0.0 P6: 00000000 P7: 040cfeec P8: c0000005 P9: 00000008 P10: Attached files: These files may be available here: C:\Users\user\AppData\Local\Microsoft\Windows\WER\ReportArchive\AppCrash_Agile1pAgent.exe_f98e4c25ce811f8566782c5b0a78d4dd8c9d_1d49779f Analysis symbol: Rechecking for solution: 0 Report Id: 80af2786-b749-11e4-af31-2c27d7202687 Report Status: 0

Any ideas? - it's putting me off the purchase at the moment.

Win7 32bit SP1